GET - https://v2.api-community-tu.org/api/paymentdemand/{id}
Get an individual payment demand.
{ "Id": 1, "ContactId": 1234, "StatusId": 1, "SubscriptionId": 567, "TotalAmount": 50.0, "PaidAmount": 0.0, "IssueDate": "2026-04-17T00:00:00+01:00", "Reason": null}