1. Open https://console.firebase.google.com

2. Select your Firebase project

3. Select Authentication -> Sign-In method

4. Enable Google Login

5. Mobile OTP Login (Enable phone Authentication)

6. Select Project Setting

7. Genrate SHA1 and SHA256 key

*********** For Debug App **********

Open Android Studio goto terminal and copy paste the below command lines and hit enter

keytool -list -v -keystore C:\Users\{your computer user name}\.android\debug.keystore -alias androiddebugkey -storepass android -keypass android

Then Copy Your SHA1 and SHA256 Key and paste into FIrebase

*********** For Live App **********

1. Open Google Play Console

2. Click your application.

3. Click Release Management / App Signing

4. Copy Both Key and Paste in Firebase App Setting

8. Setup Saftenet For Phone Authentication

goto app check and register with SafetyNet

Allow Privacy Policy and Save it