How to show pull down button menu in IOS 14 swift

Question

I created a pull down button like below

@IBOutlet weak var pullDownButton: UIButton!

Then I called a method from viewDidLoad() to configure pull down menu reference

func setupMenu() {
    let add = UIAction(title: "Add", image: UIImage(systemName: "plus")) { _ in
        self.showToast(message: "Add", seconds: 1.0)
    }
    
    let edit = UIAction(title: "Edit", image: UIImage(systemName: "pencil")) { _ in
        self.showToast(message: "Edit", seconds: 1.0)
    }
    
    let delete = UIAction(title: "Delete", image: UIImage(systemName: "minus")) { _ in
        self.showToast(message: "Delete", seconds: 1.0)
    }
    
    let menu = UIMenu(title: "Menu", children: [add, edit, delete])
    pullDownButton.menu = menu
    pullDownButton.showsMenuAsPrimaryAction = true
}

But I am unable to show the pull down menu upon long press or simple press.

Is there any way to show the pull down menu