400: invalid request (The device name is to control is missing plase check URL) plez help to solve problem

  I have generated the api and test it many times 

All these works success{1} but while creating credential there is api key and device name - submit message showing even if new api generated.

Are you trying to connect with wifi module. Right?
If am right, check your internet connection.

Cheacked and api test is also work but that message showing again and again.