The API will return a code=0 response code on success and a non-0 response code on error.
In return, you will get the specific error information in the returned msg
Example of successful response:{"code": 0, "data": {}, "msg": ""}
Example of response error:{"code": 1008790001, "msg": "Out trade number existing duplicate"}
Note: The error code returned by each error request will be different.