Hello,
It’s for the posts categories only, not for the product categories. Take it into account.
Read the documentation https://xstore.helpscoutdocs.com/article/27-mega-menu and “Subcategories with the posts” item description.
Also, you can use the Elementor page builder instead of the WPBakery (https://xstore.helpscoutdocs.com/article/47-static-blocks) to build the mega menu content https://youtu.be/f07MBdnFPfk and use tabs for example to create something similar.
Regards