Создание динамической кнопки

public class MainActivity extends AppCompatActivity {
 
    Button btn;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
 
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main_menu, menu);
        return true;
    }
 
    public void onMn1Click(MenuItem item){
        LinearLayout layout = (LinearLayout) findViewById(R.id.myLayout);
 
        ConstraintLayout.LayoutParams param = new ConstraintLayout.LayoutParams(ConstraintLayout.LayoutParams.WRAP_CONTENT, ConstraintLayout.LayoutParams.WRAP_CONTENT);
      //  Toast.makeText(this,"Hello world", Toast.LENGTH_LONG).show();
        btn = new Button(this);
        btn.setText("Button");
        param.setMargins(150, 150, 0, 0);
        btn.setLayoutParams(param);
        btn.setX(100);
        btn.setY(500);
        layout.addView(btn);
 
        /**/
    }
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {}