how to add my menu class to my MainWindow?

[saman_artorious]

I created a menu inside my mainwindow:

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    Menu *settingsMenu = new Menu(this);
//    settingsMenu->show();

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    Menu *settingsMenu = new Menu(this);
//    settingsMenu->show();

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it works fine. But now I decided to create a menu class and add the menu creation code in that class.
the menu class I created also inherits QMainWindow. When I create an instance of it in the MainWindow constructor, it doesn't show anything.
of course if I call the show() method it will create it in a separate window.

How can I merge the menu class to the main window?

Menu::Menu(QWidget *parent) :
        QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
 
    createActions();
    createMenus();
}

Menu::Menu(QWidget *parent) :
        QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    createActions();
    createMenus();
}

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