I successfully implemented Android's push notifications with ACS and Firebase. When I build my app as development, everything works fine, I subscribe successfully to channel. But when I switch to production and install the app manually(without release to Play Store, for final test), app keeps showing error: Failed to register for push! Failed receiving GCM senderId. Max retry tine reaches.
I don't understand why this error shows up, I have all set up properly, I tried to create/delete app in Firebase/Google console, but nothing helped.
Please help me.