dhtmlxMenu Vertical Scrollbar

Is it possible with the dhtmlxMenu to have a vertical scrollbar? I have a menu attached to a layout cell that has more items that can be viewed when the layout cell width is decreased and the user may not be aware there are more menu options. In the attached screenshot there is a menu item to the right that is hidden if the layout cell width is reduced

image
image

Unfortunately it is not available to add the scrollbar in the menu