Android ASAP add-on - User Auth issue

Android ASAP add-on - User Auth issue

Hello, I am faced the issue while configuring user auth via JWT in my app.
Regarding of Zoho Asap docs, and issue debbuging page, I am trying to authentificate my user in ASAP Zoho SDK inside my app. 
The issue is: I am always getting: Response from HttpUrlConnection {"error":"invalid_request"}

Steps I did: 
1. Enabled JWT in Zoho Desk settings.
2. Paste there my url, which generates JWT ( https://api-devel.dmates.io/api/zoho/jwt ). To get JWT from the request, it required the @Query user_token param to be passed. 
3. Secret key is stored correctly.