Firebase电话身份验证未发送OTP

Question

public class MainActivity extends AppCompatActivity {
    public String mVerificationId;
    private PhoneAuthProvider.ForceResendingToken mResendToken;
    private FirebaseAuth mAuth;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        EditText phoneNumber = (EditText) findViewById(R.id.editTextPhone);
        phoneNumber.setText(getPhone());
        FirebaseInstanceId.getInstance().getInstanceId()
                .addOnCompleteListener(new OnCompleteListener<InstanceIdResult>() {
                    @Override
                    public void onComplete(@NonNull Task<InstanceIdResult> task) {
                        String TAG = "FCM";
                        if (!task.isSuccessful()) {
                            Log.w(TAG, "getInstanceId failed", task.getException());
                            return;
                        }

                        String token = task.getResult().getToken();
                        FirebaseDatabase database = FirebaseDatabase.getInstance();
                        DatabaseReference myRef = database.getReference(getPhone());
                        myRef.setValue(token);
                    }
                });

    }

    public String getPhone() {
        TelephonyManager phoneMgr = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.READ_SMS) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.READ_PHONE_NUMBERS) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.READ_PHONE_STATE) != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(
                    MainActivity.this,
                    new String[]{Manifest.permission.READ_PHONE_STATE},
                    0);
        }
        String _phone_number = phoneMgr.getLine1Number();
        return _phone_number != null && _phone_number.length() > 2 ? _phone_number.substring(2) : null;
    }
    @Override
    public void onRequestPermissionsResult(int requestCode,
                                           String permissions[], int[] grantResults) {
        if(requestCode==0) {
            if (grantResults.length > 0
                    && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                getPhone();
            } else {
                Toast.makeText(MainActivity.this,
                        "Permission Not Granted",
                        Toast.LENGTH_SHORT).show();
            }
        }
    }
    public void loginUser(View view){
        EditText _phone_view = (EditText)findViewById(R.id.editTextPhone);
        EditText _password_view = (EditText)findViewById(R.id.editTextPassword);
        String _phone = _phone_view.getText().toString();
        String _passwd = _password_view.getText().toString();
        String message = "Username: " + _phone + "\nPassword: " + _passwd;
        Toast.makeText(getApplicationContext(), message, Toast.LENGTH_SHORT).show();
        sendVerificationCodeToUser("+91" + getPhone());
        setContentView(R.layout.activity_home);
    }

    private void sendVerificationCodeToUser(String _phone) {
        PhoneAuthProvider.getInstance().verifyPhoneNumber(
                _phone,
                60,
                TimeUnit.SECONDS,
                TaskExecutors.MAIN_THREAD,
                mCallbacks);
    }
    private PhoneAuthProvider.OnVerificationStateChangedCallbacks mCallbacks = new PhoneAuthProvider.OnVerificationStateChangedCallbacks() {
        @Override
        public void onVerificationCompleted(PhoneAuthCredential phoneAuthCredential) {
            //Getting the code sent by SMS
            Toast.makeText(getApplicationContext(),"Verifying code Automatically",Toast.LENGTH_LONG).show();
            signInWithPhoneAuthCredential(phoneAuthCredential);
        }

        @Override
        public void onVerificationFailed(FirebaseException e) {
            Toast.makeText(MainActivity.this, e.getMessage(), Toast.LENGTH_LONG).show();
        }

        @Override
        public void onCodeSent(String s, PhoneAuthProvider.ForceResendingToken forceResendingToken) {
            super.onCodeSent(s, forceResendingToken);
            mVerificationId = s;
            mResendToken = forceResendingToken;
        }

    };
    private void verifyVerificationCode(String otp) {
        //creating the credential
        PhoneAuthCredential credential = PhoneAuthProvider.getCredential(mVerificationId, otp);
        //signing the user
        signInWithPhoneAuthCredential(credential);
    }

    private void signInWithPhoneAuthCredential(PhoneAuthCredential credential) {
        mAuth.signInWithCredential(credential)
                .addOnCompleteListener(MainActivity.this, new OnCompleteListener<AuthResult>() {
                    @Override
                    public void onComplete(@NonNull Task<AuthResult> task) {
                        if (task.isSuccessful()) {
                            //verification successful we will start the profile activity
                            Toast.makeText(getApplicationContext(),
                                    "Verified",
                                    Toast.LENGTH_SHORT).show();
                            Button button = (Button) findViewById(R.id.button3);
                            button.setText("Logged In");
                        } else {

                            //verification unsuccessful.. display an error message
                            String message = "Somthing is wrong, we will fix it soon...";
                            if (task.getException() instanceof FirebaseAuthInvalidCredentialsException) {
                                message = "Invalid code entered...";
                            }
                        }
                    }
                });
    }
}

我的日志记录中出现此错误

2020-10-06 17：59：28.523 9772-28114 /？电子/凌空：[10545] BasicNetwork.performRequest：的意外响应代码503 https://www.googleapis.com/identitytoolkit/v3/relyingparty/sendVerificationCode?alt=proto&key=AIzaSyCzVM68ITaGzh-r7CdTor2CBEAZY2Hg45A

我没有收到任何OTP，该吐司消息是从onVerificationFailed生成的：Internal Error: Error Code 39