Phone Number Authentication in Android With Firebase (7 Steps)

You can use Firebase Authentication to sign in a user by sending an SMS message to the user’s phone. The user signs in using a one-time code contained in the SMS message.

Step1:Create XML FIle For Mobile Number Authentication

Step 2: Create Variable

Step3: Pass Mobile Number to sendverifivcation method

Step 4: Create Send Verification method

Step 5: Create an instance of OnVerificationStateChangedCallbacks

Step 6: Create Verify Code method

Step 7: After you get a PhoneAuthCredential object, whether in the onVerificationCompleted callback or by calling PhoneAuthProvider.getCredential, complete the sign-in flow by passing the PhoneAuthCredential object to FirebaseAuth.signInWithCredential: