i want to send email verfication to the new user. i am using firebase authentication. I have tried in this way, but it's giving me problem. it's not working
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (requestCode == RC_SIGN_IN) {
        IdpResponse response = IdpResponse.fromResultIntent(data);
        System.out.println("Respuesta: "+response);
                if (resultCode == RESULT_OK) {
                    // Successfully signed in
                    if (response.isNewUser()){
                        System.out.println("Eres nuevo");
                        auth.sendEmailVerification();
Here is the error
Attempt to invoke virtual method 'com.google.android.gms.tasks.Task com.google.firebase.auth.FirebaseUser.sendEmailVerification()' on a null object reference
 
    