App is crashing when we enter the phone number and click next

[ProfessorDemo]

we have only completed part 2 but we are getting issues. please HELP!!!!! this is our code

package com.example.hospitalapp;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle; import android.util.Log; import android.view.View; import android.widget.Button; import android.widget.EditText; import android.widget.ProgressBar; import android.widget.TextView; import android.widget.Toast;

import com.google.firebase.FirebaseException; import com.google.firebase.auth.FirebaseAuth; import com.google.firebase.auth.PhoneAuthCredential; import com.google.firebase.auth.PhoneAuthProvider; import com.rilixtech.widget.countrycodepicker.CountryCodePicker;

import java.util.concurrent.TimeUnit;

public class Register extends AppCompatActivity { public static final String TAG = "TAG"; EditText phoneNumber,codeEnter; FirebaseAuth fAuth; Button nextBtn; ProgressBar progressBar; TextView state; CountryCodePicker codePicker; String VerificationID; PhoneAuthProvider.ForceResendingToken token;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_register);
    fAuth = FirebaseAuth.getInstance();
    phoneNumber = findViewById(R.id.phone);
    codeEnter = findViewById(R.id.codeEnter);
    progressBar = findViewById(R.id.progressBar);
    nextBtn = findViewById(R.id.nextBtn);
    codePicker = findViewById(R.id.ccp);

    nextBtn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if(!phoneNumber.getText().toString().isEmpty() && phoneNumber.getText().toString().length()==10){

                String phoneNum = "+"+codePicker.getSelectedCountryCode() + phoneNumber.getText().toString();
                Log.d(TAG, "onClick: Phone NO -> "+ phoneNum);
                progressBar.setVisibility(View.VISIBLE);
                state.setText("Sending OTP");
                state.setVisibility(View.VISIBLE);
                requestOTP(phoneNum);

            }else {
                phoneNumber.setError("Phone Number is not valid");

            }
        }
    });

}

private void requestOTP(String phoneNum) {
    PhoneAuthProvider.getInstance().verifyPhoneNumber(phoneNum, 60L, TimeUnit.SECONDS, this, new PhoneAuthProvider.OnVerificationStateChangedCallbacks() {
        @Override
        public void onCodeSent(String s, PhoneAuthProvider.ForceResendingToken forceResendingToken) {
            super.onCodeSent(s, forceResendingToken);
            progressBar.setVisibility(View.GONE);
            state.setVisibility(View.GONE);
            codeEnter.setVisibility(View.VISIBLE);
            VerificationID = s;
            token = forceResendingToken;
        }

        @Override
        public void onCodeAutoRetrievalTimeOut(String s) {
            super.onCodeAutoRetrievalTimeOut(s);
        }

        @Override
        public void onVerificationCompleted(PhoneAuthCredential phoneAuthCredential) {

        }

        @Override
        public void onVerificationFailed(FirebaseException e) {
            Toast.makeText(Register.this,"Cannot Create Account" + e.getMessage(),Toast.LENGTH_SHORT).show();
        }
    });

}

}

[bikashthapa01]

please share the log message when the app crashed.