Google Sign In error 12500

Question

I am trying to integrate Google Sign In into my app. I don\'t have a back-end server, I am just getting the details of the logged on Google Account to my app.

I firs

Answer 1

I was stuck of this for a while.

Make sure these step are performed-

Correct SHA key is saved on Firebase Console.
Valid reversed client id.
from fcm console=>select app=>from authentication=>enable google sign-in method