Vertical menu scroll bar

Hello! The theme allows you to make a vertical menu, which is very cool. But, if the menu has a large page, it doesn’t scroll. For example, if a user sits on a website through a laptop, he will have a problem with scrolling. Or the user may not even be aware of additional menu pages due to the lack of a scroll pointer. Help me please. How to add a scroll wheel or scroll button in the vertical menu. Thank!
Example

• This topic was modified 7 years, 2 months ago by vens007.