Estou com erro ao utilizar o findViewById em um fragment

Quando vou executar o App ele Fecha!

package com.example.myapplication.Fragments;
import android.os.Bundle;
import androidx.fragment.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageButton;
import com.example.myapplication.R;

/**

  • A simple {@link Fragment} subclass.
    */
    public class CaoFragment extends Fragment {

    private ImageButton buttonCao;

    public CaoFragment() {

    }
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
    Bundle savedInstanceState) {

     View view = inflater.inflate(R.layout.fragment_cao, container, false);
     buttonCao = view.findViewById(R.id.buttonCao);
     return view;
    

    }
    }

Erro
at com.example.myapplication.Fragments.CaoFragment.onCreateView(CaoFragment.java:30)