I attached a small BSV. It can be used to discover the issue.
It needs an API-key to be entered in SystemSettings. I will send it via PM.
The zip also contains the expected JSON-file.
Request "GetListPayments" will not return the “_embedded” payments.
It returns only the “count”.
The other request “GetPayment” works fine. It is retrieving just 1 payment.
ps.
I also asked support to assist.