Ihave this error :Attempt to invoke virtual method 'void com.hbb20.CountryCodePicker.registerCarrierNumberEditText(android.widget.EditText)' on a null object reference

package com.example.geolab;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

import com.hbb20.CountryCodePicker;

public class PhoneLoginActivity extends AppCompatActivity {

private CountryCodePicker ccp;
private EditText userPhoneNumber;
private Button cuntiniueToVerify;
@Override
protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

InitializeFields();

cuntiniueToVerify.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view)
{
Intent OTPintent = new Intent(PhoneLoginActivity.this,OTPActivity.class);
OTPintent.putExtra("mobile",ccp.getFullNumberWithPlus().replace(" ",""));
startActivity(OTPintent);
}
});

}

private void InitializeFields()
{
userPhoneNumber = (EditText) findViewById(R.id.phone_number_id);
ccp = (CountryCodePicker) findViewById(R.id.ccp);
ccp.registerCarrierNumberEditText(userPhoneNumber);
cuntiniueToVerify = (Button) findViewById(R.id.cuntiniue_button);
}

}

//------------------------------------------------------layout-------------------------------------------