RadForm custom add RadTitleBar

I want to add RadTitleBar to the RadForm, so I'v created a RadTitleBarElement variable, how do i add it to RadForm(FormElement)?

My goal is to add a close, minimize, and maximize function  to the RadForm.

 public RadForm1()
        {
            InitializeComponent();

            
            titleBar = new RadTitleBarElement();

            titleBar.FillPrimitive.Visibility = ElementVisibility.Hidden;
            titleBar.MaxSize = new Size(0, 30);
            titleBar.Children[1].Visibility = ElementVisibility.Hidden;
            titleBar.AllowResize = false;
            titleBar.CloseButton.Parent.PositionOffset = new SizeF(0, 0);
            titleBar.CloseButton.MinSize = new Size(10, 10); 
            titleBar.CloseButton.ButtonFillElement.Visibility = ElementVisibility.Collapsed;

            titleBar.MinimizeButton.MinSize = new Size(10, 10);
            titleBar.MinimizeButton.ButtonFillElement.Visibility = ElementVisibility.Collapsed;

            titleBar.MaximizeButton.MinSize = new Size(10, 10);
            titleBar.MaximizeButton.ButtonFillElement.Visibility = ElementVisibility.Collapsed;

            titleBar.CloseButton.SetValue(RadFormElement.IsFormActiveProperty, true);
            titleBar.MinimizeButton.SetValue(RadFormElement.IsFormActiveProperty, true);
            titleBar.MaximizeButton.SetValue(RadFormElement.IsFormActiveProperty, true);
            titleBar.BackColor = Color.Red;
            titleBar.Close += new TitleBarSystemEventHandler(titleBar_Close);
            titleBar.Minimize += new TitleBarSystemEventHandler(titleBar_Minimize);

            titleBar.MaximizeRestore += new TitleBarSystemEventHandler(titleBar_MaximizeRestore);

    
            this.RadFormElement ？？？？？
        }