Theta V API error message for every commands/execute

THETA API Usage
5

As Il said, i’m following this tuto : Using the THETA Web API without programming (Remote photo app)

And no headers are asked. Plus, I don’t even know exactly how to use headers. Should I try one ?
What does mean “passing the header” ?

Rest of the code :

Basic Request Settings :
POST
http://192.168.1.1/osc/commands/execute

Headers :
None

Body :
Custom Text
text/json
{“name”: “camera.takePicture”, “parameters”: {} }

Response :
picture failed with status code 400 (Bad Request).

{“error”:{“code”:“unknownCommand”,“message”:“Command executed is unknown.”},“name”:“unknown”,“state”:“error”}