Android Studio – android button id declaration

I have set the button id in xml file but while I tried to find the id of the button it showing an error
xml file

<androidx.appcompat.widget.AppCompatButton
        android:id="@+id/btnrotation"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/rorationbtn"
        android:layout_below="@+id/imgbox"
        android:layout_centerInParent="true"
        android:layout_marginTop="50dp">
    </androidx.appcompat.widget.AppCompatButton>

java file

public class rotation extends AppCompatActivity {
    AppCompatButton rotate;
    ImageView imgbox;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_rotation);
        getSupportActionBar().setTitle("Rotation");
        imgbox=findViewById(R.id.imgbox);
        rotate=findViewById(R.id.btnrotation);

    }

error
does not contain a declaration with id ‘btnrotation’