title: How to resend SMS verification in Firebase Phone Authentication Android?
body: <p>According to Firebase documentation (<a href="https://firebase.google.com/docs/auth/android/phone-auth#send-a-verification-code-to-the-users-phone" rel="noreferrer">https://firebase.google.com/docs/auth/android/phone-auth#send-a-verification-code-to-the-users-phone</a>), there is <code>callback</code> for handling the phone number authentication.</p>
  
  <pre><code>mCallbacks = new PhoneAuthProvider.OnVerificationStateChangedCallbacks() {
  
      @Override
      public void onVerificationCompleted(PhoneAuthCredential credential) {
  
          Log.d(TAG, "onVerificationCompleted:" + credential);
          signInWithPhoneAuthCredential(credential);
      }
  
      @Override
      public void onVerificationFailed(FirebaseException e) {
  
          Log.w(TAG, "onVerificationFailed", e);
      }
  
      @Override
      public void onCodeSent(String verificationId,
                             PhoneAuthProvider.ForceResendingToken token) {
  
          Log.d(TAG, "onCodeSent:" + verificationId);
  
          // Save verification ID and resending token so we can use them later
          mVerificationId = verificationId;
          mResendToken = token;
      }
  };
  </code></pre>
  
  <p>My question is on <code>onCodeSent</code> method. It said on the doc here (<a href="https://firebase.google.com/docs/reference/android/com/google/firebase/auth/PhoneAuthProvider.ForceResendingToken" rel="noreferrer">https://firebase.google.com/docs/reference/android/com/google/firebase/auth/PhoneAuthProvider.ForceResendingToken</a>) </p>
  
  <p>that the <code>token</code> can be used to force re-sending an SMS verification code. However, after doing some research on the doc I still don't know how.</p>
  
  <p>I would like to ask how to use this <code>token</code> to resend the SMS verification ?</p>