Hello,
You create a menu in Appearance > Menu and set it as mobile.
Then you switch to the mobile view of the Header Builder and add Mobile menu element in which you enable/disable search and categories menu. https://xtemos.com/docs/woodmart/header-builder/
https://xtemos.com/docs/woodmart/header-builder/header-responsive-settings/
Mega-menu blocks are created in HTML, however, the mobile menu does not support mega menu blockshttps://xtemos.com/docs/woodmart/html-blocks-2/
Best Regards