Adding toolbar in toolbartray progarmmatically in wpf

ToolBarTray tray = new ToolBarTray { Orientation = Orientation.Vertical };
ToolBar toolbar = new ToolBar() { Width = double.NaN, Height = double.NaN};
          
Button btnViewDetails = new Button() { Width = 200, Height = 30, Content = "View Details" };
Button btnAddModule = new Button() { Width = 200, Height = 30, Content = "Add Module" };
Button btnRemoveModule = new Button() { Width = 200, Height = 30, Content = "Remove Module" };
Button btnSendCommunication = new Button() { Width = 200, Height = 30, Content = "Send Communication" };

toolbar.Items.Add(btnViewDetails);
toolbar.Items.Add(btnAddModule);
toolbar.Items.Add(btnRemoveModule);
toolbar.Items.Add(btnSendCommunication);
toolbar.Band = 0;

//adding toolbar into tray