How to add a new tab to the WinForms TabbedMDIManager as like Browser?

// Initialize 
private Syncfusion.Windows.Forms.Tools.TabbedMDIManager tabbedMDIManager1;
TabControlAdv tabControl;
Form form1 = new Form();
Form form2 = new Form();
Form form3 = new Form();
Form form4 = new Form();
Form form5 = new Form(); 
 
// TabbedMDIManager
this.tabbedMDIManager1 = new Syncfusion.Windows.Forms.Tools.TabbedMDIManager();
this.tabbedMDIManager1.AttachedTo = this;
 
// TabbedMDIManager Style
this.tabbedMDIManager1.TabStyle = typeof(Syncfusion.Windows.Forms.Tools.TabRendererWorkbookMode);
this.IsMdiContainer = true;
 
// For Child Tab
form1.Text = "tabpage1";
form2.Text = "tabpage2";
form3.Text = " Add New Tab ";
 
form1.MdiParent = this;
form2.MdiParent = this;
form3.MdiParent = this;
 
form2.Show();
form3.Show();
form1.Show();
 
this.tabbedMDIManager1.TabControlAdded += TabbedMDIManager1_TabControlAdded;
//For Adding New Tab
private void TabbedMDIManager1_TabControlAdded(object sender, 
Syncfusion.Windows.Forms.Tools.TabbedMDITabControlEventArgs args)
{
  tabControl = new TabControlAdv();
  tabControl = args.TabControl;
  //Tab size
  tabControl.ItemSize = new Size(30, 30);
  //Create New Tab, when click the Plus(+) tab
  tabControl.Click += TabControl_Click;
}
 
/// <summary>
/// Event to handle the Add new tab page on click
/// </summary>
private void TabControl_Click(object sender, EventArgs e)
{
  //Add New TabPage
  if(tabControl.SelectedTab.Text == "Add New Tab")
  {
    Form[] forms = this.MdiChildren;
    foreach (Form c in forms)
    {
      if (c.Text == "Add New Tab")
      {
        form4 = new Form();
        form4.Text = "New Tab";
        form4.MdiParent = this;
        form4.Show();
        form3.Close();
        form3 = new Form();
        form3.Text = "Add New Tab";
        form3.MdiParent = this;
        break;
      }
    }
  }
}

' Initialize
Private tabbedMDIManager1 As Syncfusion.Windows.Forms.Tools.TabbedMDIManager
Private tabControl As TabControlAdv
Private form3 As New Form()
Private form4 As New Form()
Private form5 As New Form()
 
' TabbedMDIManager
Me.tabbedMDIManager1 = New Syncfusion.Windows.Forms.Tools. TabbedMDIManager()
Me.tabbedMDIManager1.AttachedTo = Me
 
' TabbedMDIManager Style
Me.tabbedMDIManager1.TabStyle = GetType(Syncfusion.Windows.Forms.Tools.TabRendererWorkbookMode)
Me.IsMdiContainer = True
 
' For Child Tab
Dim form1 As New Form ()
Dim form2 As New Form ()
 
form1.Text = "tabpage1"
form2.Text = "tabpage2"
form3.Text = "Add New Tab"
 
form1.MdiParent = Me
form2.MdiParent = Me
form3.MdiParent = Me
 
form2.Show()
form3.Show()
form1.Show()
 
AddHandler Me.tabbedMDIManager1.TabControlAdded, AddressOf TabbedMDIManager1_TabControlAdded
'For Adding New Tab
Private Sub TabbedMDIManager1_TabControlAdded(ByVal sender As Object, ByVal args As Syncfusion.Windows.Forms.Tools.TabbedMDITabControlEventArgs)
  tabControl = New TabControlAdv()
  tabControl = args.TabControl
  'Tab size
  tabControl.ItemSize = New Size(30, 30)
  'Create New Tab, when click the Plus (+) tab
  AddHandler tabControl.Click, AddressOf TabControl_Click
End Sub
 
''' <summary>
''' Event to handle the Add new tab page on click
''' </summary>
Private Sub TabControl_Click(ByVal sender As Object, ByVal e As EventArgs)
  'Add New TabPage
  If tabControl.SelectedTab.Text = "Add New Tab" Then
    Dim forms() As Form = Me.MdiChildren
    For Each c As Form In forms
      If c.Text = "Add New Tab" Then
        form4 = New Form()
        form4.Text = "New Tab"
        form4.MdiParent = Me
        form4.Show()
        form3.Close()
        form3 = New Form()
        form3.Text = "Add New Tab"
        form3.MdiParent = Me
        Exit For
      End If
    Next c
  End If
End Sub