I read carefully the documentation about the Rest API, however, I can't find the way to Login user sdpapi/auth module.

It's written on the doc : 

AUTHTOKEN is returned from the Login operation.

So I try to use the Login Operation which is documented below : 

However, the documentation does not describe the "Input" details so every time I try to log with any JSON string, I get this error message :

{"operation":{"result":{"message":"Username and/or password provided is wrong","status":"Failed"}}}

Does anyone have a tip / advice or real case ?

My goal behind is to provide a PHP portal to our technicians to let them quickly create X request in one click. So I can't use the TECHNICIAN_KEY because it must be their personal account who create the requests.

Thanks for your help,

Yannick