DonationExternal

Billing9 EndpointsBilling / DonationExternal

Get available donation amounts and feature status

GET/api/invoice/external/donation/amounts

Responses

200Returns available donation amounts

Request

curl --request GET \
  --url https://your-instance.iw-erp.de/api/invoice/external/donation/amounts \
  --header 'x-iw-jwt-token: <TOKEN>'

const options = {method: 'GET', headers: {'x-iw-jwt-token': '<TOKEN>'}};

fetch('https://your-instance.iw-erp.de/api/invoice/external/donation/amounts', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://your-instance.iw-erp.de/api/invoice/external/donation/amounts"

headers = {"x-iw-jwt-token": "<TOKEN>"}

response = requests.get(url, headers=headers)

print(response.text)

<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('GET', 'https://your-instance.iw-erp.de/api/invoice/external/donation/amounts', [
  'headers' => [
    'x-iw-jwt-token' => '<TOKEN>',
  ],
]);

echo $response->getBody();

using System.Net.Http.Headers;
var client = new HttpClient();
var request = new HttpRequestMessage
{
  Method = HttpMethod.Get,
  RequestUri = new Uri("https://your-instance.iw-erp.de/api/invoice/external/donation/amounts"),
  Headers =
  {
    { "x-iw-jwt-token", "<TOKEN>" },
  },
};
using (var response = await client.SendAsync(request))
{
  response.EnsureSuccessStatusCode();
  var body = await response.Content.ReadAsStringAsync();
  Console.WriteLine(body);
}

OkHttpClient client = new OkHttpClient();

Request request = new Request.Builder()
  .url("https://your-instance.iw-erp.de/api/invoice/external/donation/amounts")
  .get()
  .addHeader("x-iw-jwt-token", "<TOKEN>")
  .build();

Response response = client.newCall(request).execute();

package main

import (
	"fmt"
	"net/http"
	"io"
)

func main() {

	url := "https://your-instance.iw-erp.de/api/invoice/external/donation/amounts"

	req, _ := http.NewRequest("GET", url, nil)

	req.Header.Add("x-iw-jwt-token", "<TOKEN>")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

Dart with the iw_erp_api package

import 'package:iw_erp_api/clients/billing_donation_external_controller.dart';
import 'package:iw_erp_api/logic/iw_api_state.dart';

IwApiState().host = 'your-instance.iw-erp.de';
IwApiState().currentJwtApiToken = '<TOKEN>';

final result = await BillingDonationExternalController.getAvailableAmounts();
if (result.success) {
  print(result.data);
}

Initiate a donation with payment

POST/api/invoice/external/donation/initiate

Responses

200Creates a donation and returns payment redirect URL

Request

curl --request POST \
  --url https://your-instance.iw-erp.de/api/invoice/external/donation/initiate \
  --header 'x-iw-jwt-token: <TOKEN>'

const options = {method: 'POST', headers: {'x-iw-jwt-token': '<TOKEN>'}};

fetch('https://your-instance.iw-erp.de/api/invoice/external/donation/initiate', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://your-instance.iw-erp.de/api/invoice/external/donation/initiate"

headers = {"x-iw-jwt-token": "<TOKEN>"}

response = requests.post(url, headers=headers)

print(response.text)

<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://your-instance.iw-erp.de/api/invoice/external/donation/initiate', [
  'headers' => [
    'x-iw-jwt-token' => '<TOKEN>',
  ],
]);

echo $response->getBody();

using System.Net.Http.Headers;
var client = new HttpClient();
var request = new HttpRequestMessage
{
  Method = HttpMethod.Post,
  RequestUri = new Uri("https://your-instance.iw-erp.de/api/invoice/external/donation/initiate"),
  Headers =
  {
    { "x-iw-jwt-token", "<TOKEN>" },
  },
};
using (var response = await client.SendAsync(request))
{
  response.EnsureSuccessStatusCode();
  var body = await response.Content.ReadAsStringAsync();
  Console.WriteLine(body);
}

OkHttpClient client = new OkHttpClient();

Request request = new Request.Builder()
  .url("https://your-instance.iw-erp.de/api/invoice/external/donation/initiate")
  .post(null)
  .addHeader("x-iw-jwt-token", "<TOKEN>")
  .build();

Response response = client.newCall(request).execute();

package main

import (
	"fmt"
	"net/http"
	"io"
)

func main() {

	url := "https://your-instance.iw-erp.de/api/invoice/external/donation/initiate"

	req, _ := http.NewRequest("POST", url, nil)

	req.Header.Add("x-iw-jwt-token", "<TOKEN>")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

Dart with the iw_erp_api package

import 'package:iw_erp_api/clients/billing_donation_external_controller.dart';
import 'package:iw_erp_api/logic/iw_api_state.dart';

IwApiState().host = 'your-instance.iw-erp.de';
IwApiState().currentJwtApiToken = '<TOKEN>';

final result = await BillingDonationExternalController.initiateDonation(amount: 42, donorName: '…', donorEmail: '…');
if (result.success) {
  print(result.data);
}

Payment gateway notification callback

GET/api/invoice/external/donation/notify/{token}/{paymentProvider}

Path parameters

`token`requiredstring
`paymentProvider`requiredstring

Responses

200Processes payment notification

Request

curl --request GET \
  --url https://your-instance.iw-erp.de/api/invoice/external/donation/notify/42/42 \
  --header 'x-iw-jwt-token: <TOKEN>'

const options = {method: 'GET', headers: {'x-iw-jwt-token': '<TOKEN>'}};

fetch('https://your-instance.iw-erp.de/api/invoice/external/donation/notify/42/42', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://your-instance.iw-erp.de/api/invoice/external/donation/notify/42/42"

headers = {"x-iw-jwt-token": "<TOKEN>"}

response = requests.get(url, headers=headers)

print(response.text)

<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('GET', 'https://your-instance.iw-erp.de/api/invoice/external/donation/notify/42/42', [
  'headers' => [
    'x-iw-jwt-token' => '<TOKEN>',
  ],
]);

echo $response->getBody();

using System.Net.Http.Headers;
var client = new HttpClient();
var request = new HttpRequestMessage
{
  Method = HttpMethod.Get,
  RequestUri = new Uri("https://your-instance.iw-erp.de/api/invoice/external/donation/notify/42/42"),
  Headers =
  {
    { "x-iw-jwt-token", "<TOKEN>" },
  },
};
using (var response = await client.SendAsync(request))
{
  response.EnsureSuccessStatusCode();
  var body = await response.Content.ReadAsStringAsync();
  Console.WriteLine(body);
}

OkHttpClient client = new OkHttpClient();

Request request = new Request.Builder()
  .url("https://your-instance.iw-erp.de/api/invoice/external/donation/notify/42/42")
  .get()
  .addHeader("x-iw-jwt-token", "<TOKEN>")
  .build();

Response response = client.newCall(request).execute();

package main

import (
	"fmt"
	"net/http"
	"io"
)

func main() {

	url := "https://your-instance.iw-erp.de/api/invoice/external/donation/notify/42/42"

	req, _ := http.NewRequest("GET", url, nil)

	req.Header.Add("x-iw-jwt-token", "<TOKEN>")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

Dart with package:http (no controller in the iw_erp_api package)

import 'package:http/http.dart' as http;

final response = await http.get(
  Uri.parse('https://your-instance.iw-erp.de/api/invoice/external/donation/notify/42/42'),
  headers: {'x-iw-jwt-token': '<TOKEN>'},
);
print(response.body);

Payment gateway notification callback

POST/api/invoice/external/donation/notify/{token}/{paymentProvider}

Path parameters

`token`requiredstring
`paymentProvider`requiredstring

Responses

200Processes payment notification

Request

curl --request POST \
  --url https://your-instance.iw-erp.de/api/invoice/external/donation/notify/42/42 \
  --header 'x-iw-jwt-token: <TOKEN>'

const options = {method: 'POST', headers: {'x-iw-jwt-token': '<TOKEN>'}};

fetch('https://your-instance.iw-erp.de/api/invoice/external/donation/notify/42/42', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://your-instance.iw-erp.de/api/invoice/external/donation/notify/42/42"

headers = {"x-iw-jwt-token": "<TOKEN>"}

response = requests.post(url, headers=headers)

print(response.text)

<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://your-instance.iw-erp.de/api/invoice/external/donation/notify/42/42', [
  'headers' => [
    'x-iw-jwt-token' => '<TOKEN>',
  ],
]);

echo $response->getBody();

using System.Net.Http.Headers;
var client = new HttpClient();
var request = new HttpRequestMessage
{
  Method = HttpMethod.Post,
  RequestUri = new Uri("https://your-instance.iw-erp.de/api/invoice/external/donation/notify/42/42"),
  Headers =
  {
    { "x-iw-jwt-token", "<TOKEN>" },
  },
};
using (var response = await client.SendAsync(request))
{
  response.EnsureSuccessStatusCode();
  var body = await response.Content.ReadAsStringAsync();
  Console.WriteLine(body);
}

OkHttpClient client = new OkHttpClient();

Request request = new Request.Builder()
  .url("https://your-instance.iw-erp.de/api/invoice/external/donation/notify/42/42")
  .post(null)
  .addHeader("x-iw-jwt-token", "<TOKEN>")
  .build();

Response response = client.newCall(request).execute();

package main

import (
	"fmt"
	"net/http"
	"io"
)

func main() {

	url := "https://your-instance.iw-erp.de/api/invoice/external/donation/notify/42/42"

	req, _ := http.NewRequest("POST", url, nil)

	req.Header.Add("x-iw-jwt-token", "<TOKEN>")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

Dart with package:http (no controller in the iw_erp_api package)

import 'package:http/http.dart' as http;

final response = await http.post(
  Uri.parse('https://your-instance.iw-erp.de/api/invoice/external/donation/notify/42/42'),
  headers: {'x-iw-jwt-token': '<TOKEN>'},
);
print(response.body);

Download Spendenbescheinigung PDF by token

GET/api/invoice/external/donation/pdf/{id}/{token}

Path parameters

`id`requiredstring
`token`requiredstring

Responses

200Returns the Spendenbescheinigung as PDF

Request

curl --request GET \
  --url https://your-instance.iw-erp.de/api/invoice/external/donation/pdf/42/42 \
  --header 'x-iw-jwt-token: <TOKEN>'

const options = {method: 'GET', headers: {'x-iw-jwt-token': '<TOKEN>'}};

fetch('https://your-instance.iw-erp.de/api/invoice/external/donation/pdf/42/42', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://your-instance.iw-erp.de/api/invoice/external/donation/pdf/42/42"

headers = {"x-iw-jwt-token": "<TOKEN>"}

response = requests.get(url, headers=headers)

print(response.text)

<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('GET', 'https://your-instance.iw-erp.de/api/invoice/external/donation/pdf/42/42', [
  'headers' => [
    'x-iw-jwt-token' => '<TOKEN>',
  ],
]);

echo $response->getBody();

using System.Net.Http.Headers;
var client = new HttpClient();
var request = new HttpRequestMessage
{
  Method = HttpMethod.Get,
  RequestUri = new Uri("https://your-instance.iw-erp.de/api/invoice/external/donation/pdf/42/42"),
  Headers =
  {
    { "x-iw-jwt-token", "<TOKEN>" },
  },
};
using (var response = await client.SendAsync(request))
{
  response.EnsureSuccessStatusCode();
  var body = await response.Content.ReadAsStringAsync();
  Console.WriteLine(body);
}

OkHttpClient client = new OkHttpClient();

Request request = new Request.Builder()
  .url("https://your-instance.iw-erp.de/api/invoice/external/donation/pdf/42/42")
  .get()
  .addHeader("x-iw-jwt-token", "<TOKEN>")
  .build();

Response response = client.newCall(request).execute();

package main

import (
	"fmt"
	"net/http"
	"io"
)

func main() {

	url := "https://your-instance.iw-erp.de/api/invoice/external/donation/pdf/42/42"

	req, _ := http.NewRequest("GET", url, nil)

	req.Header.Add("x-iw-jwt-token", "<TOKEN>")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

Dart with the iw_erp_api package

import 'package:iw_erp_api/clients/billing_donation_external_controller.dart';
import 'package:iw_erp_api/logic/iw_api_state.dart';

IwApiState().host = 'your-instance.iw-erp.de';
IwApiState().currentJwtApiToken = '<TOKEN>';

final result = await BillingDonationExternalController.getDownloadLinkPdf('42', '42');
print(result);

Initiate a recurring donation collected via SEPA direct debit.

POST/api/invoice/external/donation/recurring/initiate

Responses

200Creates a recurring donation with a SEPA mandate

Request

curl --request POST \
  --url https://your-instance.iw-erp.de/api/invoice/external/donation/recurring/initiate \
  --header 'x-iw-jwt-token: <TOKEN>'

const options = {method: 'POST', headers: {'x-iw-jwt-token': '<TOKEN>'}};

fetch('https://your-instance.iw-erp.de/api/invoice/external/donation/recurring/initiate', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://your-instance.iw-erp.de/api/invoice/external/donation/recurring/initiate"

headers = {"x-iw-jwt-token": "<TOKEN>"}

response = requests.post(url, headers=headers)

print(response.text)

<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://your-instance.iw-erp.de/api/invoice/external/donation/recurring/initiate', [
  'headers' => [
    'x-iw-jwt-token' => '<TOKEN>',
  ],
]);

echo $response->getBody();

using System.Net.Http.Headers;
var client = new HttpClient();
var request = new HttpRequestMessage
{
  Method = HttpMethod.Post,
  RequestUri = new Uri("https://your-instance.iw-erp.de/api/invoice/external/donation/recurring/initiate"),
  Headers =
  {
    { "x-iw-jwt-token", "<TOKEN>" },
  },
};
using (var response = await client.SendAsync(request))
{
  response.EnsureSuccessStatusCode();
  var body = await response.Content.ReadAsStringAsync();
  Console.WriteLine(body);
}

OkHttpClient client = new OkHttpClient();

Request request = new Request.Builder()
  .url("https://your-instance.iw-erp.de/api/invoice/external/donation/recurring/initiate")
  .post(null)
  .addHeader("x-iw-jwt-token", "<TOKEN>")
  .build();

Response response = client.newCall(request).execute();

package main

import (
	"fmt"
	"net/http"
	"io"
)

func main() {

	url := "https://your-instance.iw-erp.de/api/invoice/external/donation/recurring/initiate"

	req, _ := http.NewRequest("POST", url, nil)

	req.Header.Add("x-iw-jwt-token", "<TOKEN>")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

Dart with the iw_erp_api package

import 'package:iw_erp_api/clients/billing_donation_external_controller.dart';
import 'package:iw_erp_api/logic/iw_api_state.dart';

IwApiState().host = 'your-instance.iw-erp.de';
IwApiState().currentJwtApiToken = '<TOKEN>';

final result = await BillingDonationExternalController.initiateRecurringDonation(amount: 42, interval: '…', donorName: '…', donorEmail: '…', accountHolder: '…', iban: '…', mandateConsent: true);
if (result.success) {
  print(result.data);
}

Get recurring donation status by token

GET/api/invoice/external/donation/recurring/{token}

Path parameters

tokenrequiredstring

Responses

200Returns recurring donation status

Request

curl --request GET \
  --url https://your-instance.iw-erp.de/api/invoice/external/donation/recurring/42 \
  --header 'x-iw-jwt-token: <TOKEN>'

const options = {method: 'GET', headers: {'x-iw-jwt-token': '<TOKEN>'}};

fetch('https://your-instance.iw-erp.de/api/invoice/external/donation/recurring/42', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://your-instance.iw-erp.de/api/invoice/external/donation/recurring/42"

headers = {"x-iw-jwt-token": "<TOKEN>"}

response = requests.get(url, headers=headers)

print(response.text)

<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('GET', 'https://your-instance.iw-erp.de/api/invoice/external/donation/recurring/42', [
  'headers' => [
    'x-iw-jwt-token' => '<TOKEN>',
  ],
]);

echo $response->getBody();

using System.Net.Http.Headers;
var client = new HttpClient();
var request = new HttpRequestMessage
{
  Method = HttpMethod.Get,
  RequestUri = new Uri("https://your-instance.iw-erp.de/api/invoice/external/donation/recurring/42"),
  Headers =
  {
    { "x-iw-jwt-token", "<TOKEN>" },
  },
};
using (var response = await client.SendAsync(request))
{
  response.EnsureSuccessStatusCode();
  var body = await response.Content.ReadAsStringAsync();
  Console.WriteLine(body);
}

OkHttpClient client = new OkHttpClient();

Request request = new Request.Builder()
  .url("https://your-instance.iw-erp.de/api/invoice/external/donation/recurring/42")
  .get()
  .addHeader("x-iw-jwt-token", "<TOKEN>")
  .build();

Response response = client.newCall(request).execute();

package main

import (
	"fmt"
	"net/http"
	"io"
)

func main() {

	url := "https://your-instance.iw-erp.de/api/invoice/external/donation/recurring/42"

	req, _ := http.NewRequest("GET", url, nil)

	req.Header.Add("x-iw-jwt-token", "<TOKEN>")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

Dart with the iw_erp_api package

import 'package:iw_erp_api/clients/billing_donation_external_controller.dart';
import 'package:iw_erp_api/logic/iw_api_state.dart';

IwApiState().host = 'your-instance.iw-erp.de';
IwApiState().currentJwtApiToken = '<TOKEN>';

final result = await BillingDonationExternalController.getRecurringDonationStatus('42');
if (result.success) {
  print(result.data);
}

Cancel a recurring donation by token

POST/api/invoice/external/donation/recurring/{token}/cancel

Path parameters

tokenrequiredstring

Responses

200Cancels a recurring donation

Request

curl --request POST \
  --url https://your-instance.iw-erp.de/api/invoice/external/donation/recurring/42/cancel \
  --header 'x-iw-jwt-token: <TOKEN>'

const options = {method: 'POST', headers: {'x-iw-jwt-token': '<TOKEN>'}};

fetch('https://your-instance.iw-erp.de/api/invoice/external/donation/recurring/42/cancel', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://your-instance.iw-erp.de/api/invoice/external/donation/recurring/42/cancel"

headers = {"x-iw-jwt-token": "<TOKEN>"}

response = requests.post(url, headers=headers)

print(response.text)

<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://your-instance.iw-erp.de/api/invoice/external/donation/recurring/42/cancel', [
  'headers' => [
    'x-iw-jwt-token' => '<TOKEN>',
  ],
]);

echo $response->getBody();

using System.Net.Http.Headers;
var client = new HttpClient();
var request = new HttpRequestMessage
{
  Method = HttpMethod.Post,
  RequestUri = new Uri("https://your-instance.iw-erp.de/api/invoice/external/donation/recurring/42/cancel"),
  Headers =
  {
    { "x-iw-jwt-token", "<TOKEN>" },
  },
};
using (var response = await client.SendAsync(request))
{
  response.EnsureSuccessStatusCode();
  var body = await response.Content.ReadAsStringAsync();
  Console.WriteLine(body);
}

OkHttpClient client = new OkHttpClient();

Request request = new Request.Builder()
  .url("https://your-instance.iw-erp.de/api/invoice/external/donation/recurring/42/cancel")
  .post(null)
  .addHeader("x-iw-jwt-token", "<TOKEN>")
  .build();

Response response = client.newCall(request).execute();

package main

import (
	"fmt"
	"net/http"
	"io"
)

func main() {

	url := "https://your-instance.iw-erp.de/api/invoice/external/donation/recurring/42/cancel"

	req, _ := http.NewRequest("POST", url, nil)

	req.Header.Add("x-iw-jwt-token", "<TOKEN>")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

Dart with the iw_erp_api package

import 'package:iw_erp_api/clients/billing_donation_external_controller.dart';
import 'package:iw_erp_api/logic/iw_api_state.dart';

IwApiState().host = 'your-instance.iw-erp.de';
IwApiState().currentJwtApiToken = '<TOKEN>';

final result = await BillingDonationExternalController.cancelRecurringDonation('42');
if (result.success) {
  print(result.data);
}

Get donation status by token

GET/api/invoice/external/donation/{token}

Path parameters

tokenrequiredstring

Responses

200Returns donation status

Request

curl --request GET \
  --url https://your-instance.iw-erp.de/api/invoice/external/donation/42 \
  --header 'x-iw-jwt-token: <TOKEN>'

const options = {method: 'GET', headers: {'x-iw-jwt-token': '<TOKEN>'}};

fetch('https://your-instance.iw-erp.de/api/invoice/external/donation/42', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://your-instance.iw-erp.de/api/invoice/external/donation/42"

headers = {"x-iw-jwt-token": "<TOKEN>"}

response = requests.get(url, headers=headers)

print(response.text)

<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('GET', 'https://your-instance.iw-erp.de/api/invoice/external/donation/42', [
  'headers' => [
    'x-iw-jwt-token' => '<TOKEN>',
  ],
]);

echo $response->getBody();

using System.Net.Http.Headers;
var client = new HttpClient();
var request = new HttpRequestMessage
{
  Method = HttpMethod.Get,
  RequestUri = new Uri("https://your-instance.iw-erp.de/api/invoice/external/donation/42"),
  Headers =
  {
    { "x-iw-jwt-token", "<TOKEN>" },
  },
};
using (var response = await client.SendAsync(request))
{
  response.EnsureSuccessStatusCode();
  var body = await response.Content.ReadAsStringAsync();
  Console.WriteLine(body);
}

OkHttpClient client = new OkHttpClient();

Request request = new Request.Builder()
  .url("https://your-instance.iw-erp.de/api/invoice/external/donation/42")
  .get()
  .addHeader("x-iw-jwt-token", "<TOKEN>")
  .build();

Response response = client.newCall(request).execute();

package main

import (
	"fmt"
	"net/http"
	"io"
)

func main() {

	url := "https://your-instance.iw-erp.de/api/invoice/external/donation/42"

	req, _ := http.NewRequest("GET", url, nil)

	req.Header.Add("x-iw-jwt-token", "<TOKEN>")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

Dart with the iw_erp_api package

import 'package:iw_erp_api/clients/billing_donation_external_controller.dart';
import 'package:iw_erp_api/logic/iw_api_state.dart';

IwApiState().host = 'your-instance.iw-erp.de';
IwApiState().currentJwtApiToken = '<TOKEN>';

final result = await BillingDonationExternalController.getDonationStatus('42');
if (result.success) {
  print(result.data);
}