Arrow change

Hi,

The First TAb (Menu) have alwas a Arrow that we can see thats includes submenus.
I would like to get a hamburger icon, which changes to a “X” if I click on it.

It is possible?

My current solution is-> to hide the arrow and add a Hamburger icon beside the Tab Name.
The Problem is here, it’s also hide the arrows in the Mobile view for submenus ??

The page I need help with: [log in to see the link]