gs-nav-trigger is a class that you must put on the element that will trigger the level of the menu. Right after the element with this block, you must put the container with class gs-nav-sub-level. You can put anything inside, but the first block in this container must be an element with class gs-nav-back-trigger. You can use unlimited levels of menu
To change the design of the whole panel, select the most parent Sliding Panel Block. In the Animation panel, you can select another appearance Effect.
When you finish adding menus, you can hide it from the admin page. For this, select the Sliding panel, and in Responsive Styles, select Hide in the Admin panel. The panel will continue to work on frontend.
All interactions are added to the menu trigger button. You can change the logic and name of classes, but be careful, do this only if you understand your actions