<Button
    android:id="@+id/button"
    android:layout_width="101dp"
    android:layout_height="85dp"
    android:layout_marginStart="132dp"
    android:layout_marginTop="148dp"
    android:onClick="pge"
    android:visibility="invisible"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    tools:ignore="MissingConstraints" />

public void pge(View view){

    msToast("Hello");

}

public void msToast(String text){
    Context context = getApplicationContext();
    int duration = Toast.LENGTH_SHORT;
    Toast toast = Toast.makeText(context, text, duration);
    toast.show();
}