How to hide the GravityKit menu
If, for some reason, you need to forcefully hide the GravityKit menu without having to mess with capabilities, then you can use the filter below:
add_filter( 'gk/foundation/admin-menu/submenus', function () { return []; }, 100 );
That will hide the menu for everyone, including yourself!
Read here how to add these code samples to your website: Where to put code samples.