Reply To: hovering on each category in the header, the sub-menus (childs) will display

Hello,

You can try creating the HTML Block as a dropdown for each category then you can set it as the HTML Block as a Dropdown by editing from the Appearance >> Menus.

Screenshot for Clarification: https://ibb.co/Bg5vfgW

You can read our detailed documentation for further help:
https://xtemos.com/docs/woodmart/html-blocks-2/#mega_menu

Best Regards