PLSQL REST Response Body not returned

I had a task to request via POST to a third party website and get the response back from the body.

I tried this and expected the callback function to return back the body from the request, No, it returns the original BODY used to make the request, not the returned BODY. I really wish IFS would improve it’s REST based functionality, I had to write a C# program and run that on a windows event to perform the task. It would be much, neater if it could be done in PL/SQL. Actually, since this is a Connect based call, it would be awesome. The documentation on the callback function is poor, it was very difficult to find the one of 5 callback methods that apply to this call. After spending a day on this, I gave up and chose the c# method, because, in the end, I had to get it done.

            Plsql_Rest_Sender_API.Call_Rest_EndPoint2(
               rest_service_ => 'https://…./{parameter1}',
               xml_ => xml,
               url_params_ => url,
               callback_func_ => 'c_my_util_api.REST_callback_Test',
               http_method_ => 'POST',
               http_req_headers_ => header_ ,
               query_parameters_ => NULL,
               header_params_ => NULL,
               incld_resp_info_ => false);