When making a request in postman - status 200, when making the same request in jmeter - status 500 and an error:
{"status":"fail","message":"Internal Server Error","system_message":"Expecting value: line 1 column 1 (char 0)"}
When making a request in postman - status 200, when making the same request in jmeter - status 500 and an error:
{"status":"fail","message":"Internal Server Error","system_message":"Expecting value: line 1 column 1 (char 0)"}
Given you send the same request you should be getting the same response.
For example I fail to see where did you get this Content-Type header in your JMeter's HTTP Header Manager
My expectation is that if you remove this header the server will stop treating the request as a JSON payload and won't return JSONDecodeError anymore
If you have troubles copying and pasting 5 headers from Postman to JMeter you can always record the API call from your browser or upstream application using JMeter Chrome Extension or JMeter's HTTP(S) Test Script Recorder