Null verification id in firebase authentication

I am creating an OTP verification app using Firebase Authentication with a phone number. I did all the stuff like add dependencies,pugin, JSON file, and connect Firebase Authentication but still have this error. please tell me what should i do.

public class MainActivity extends AppCompatActivity {

    EditText editMobileNumber;
    Button sendButton;
    FirebaseAuth mAuth;
    PhoneAuthProvider.OnVerificationStateChangedCallbacks mCallbacks;



    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mAuth=FirebaseAuth.getInstance();

        editMobileNumber=findViewById(R.id.editMobileNumber);
        sendButton=findViewById(R.id.getOTP);

        sendButton.setOnClickListener(v -> {
            String number=editMobileNumber.getText().toString().trim();
            if(number.length() != 10){

                Toast.makeText(this,"Enter a valid number",Toast.LENGTH_SHORT).show();
            }
            else{
                    otpSend(number);
            }
        }
        );

    }

    private void otpSend(String number) {
        mCallbacks = new PhoneAuthProvider.OnVerificationStateChangedCallbacks() {

            @Override
            public void onVerificationCompleted(@NonNull PhoneAuthCredential credential) {

            }

            @Override
            public void onVerificationFailed(@NonNull FirebaseException e) {

                Toast.makeText(MainActivity.this,number,Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onCodeSent(@NonNull String verificationId,
                                   @NonNull PhoneAuthProvider.ForceResendingToken token) {

                Toast.makeText(MainActivity.this,verificationId,Toast.LENGTH_SHORT).show();
                Intent i=new Intent(MainActivity.this, verifyOTP.class);
                i.putExtra("verificationId",verificationId);
                startActivity(i);
                finish();
            }
        };

        PhoneAuthOptions options =
                PhoneAuthOptions.newBuilder(mAuth)
                        .setPhoneNumber("+91" + number)       // Phone number for Otp
                        .setTimeout(60L, TimeUnit.SECONDS) // Timeout and unit
                        .setActivity(this)
                        .setCallbacks(mCallbacks)          // OnVerificationStateChangedCallbacks
                        .build();

        PhoneAuthProvider.verifyPhoneNumber(options);

    }


}

verification is on next activity. here is the code :-

public class verifyOTP extends AppCompatActivity {

PinView otpPinView;
Button resendOTPButton,verifyButton;
TextView textView;
String verificationId= getIntent().getStringExtra("verificationId"),otp;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_verify_otp);

    otpPinView=findViewById(R.id.otppinview);
    resendOTPButton=findViewById(R.id.resendOTPButton);
    verifyButton=findViewById(R.id.verifyButton);
    textView=findViewById(R.id.verifyOTP);



    textView.setOnClickListener(v -> {
        Toast.makeText(this,"it works",Toast.LENGTH_SHORT).show();
    });


    verifyButton.setOnClickListener(v ->{
        otp= Objects.requireNonNull(otpPinView.getText()).toString();

        if(otp.length() != 6){
            Toast.makeText(this,"Invalid OTP!!",Toast.LENGTH_SHORT).show();
        }
        else{
            if(verificationId != null){
                PhoneAuthCredential credential = PhoneAuthProvider.getCredential(verificationId, otp);

                FirebaseAuth.getInstance().signInWithCredential(credential)
                        .addOnCompleteListener(this, task -> {
                            if (task.isSuccessful()) {
                                // If Sign in success


                            } else {
                                // If sign in failed
                                Toast.makeText(this,"Invalid OTP!!",Toast.LENGTH_SHORT).show();
                            }
                        });

            }
        }

    });


}

}

the logcat show error is:-

1. Failed to initialize reCAPTCHA config: No Recaptcha Enterprise siteKey configured for tenant/project *

2. FATAL EXCEPTION: main java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.vivetales/com.example.vivetales.verifyOTP}: java.lang.NullPointerException: Attempt to invoke virtual method ‘java.lang.String android.content.Intent.getStringExtra(java.lang.String)’ on a null object reference