Hello,

Each submenu for the category is HTML block. So, first of all, create or edit the block for each category https://xtemos.com/docs/woodmart/html-blocks-2/ If you add new or try editing the existing one, you will see that HTML block is WP bakery template.

As soon as you have all blocks ready, navigate to Appearance > Menu, choose your category menu and add HTML title as shown here: https://xtemos.com/docs/woodmart/create-menu-2/

Please clarify the issue if you still need more information.

Best Regards