Hello,
Browse Category main links are created in Appearance > Menu > create new > add Product categories.
Next, create HTML block for each Mega menu block for each category, using the Menu Extra list element, which allows setting link choosing from the list, not inserting URL https://xtemos.com/docs/woodmart/html-blocks-2/#mega_menu
Finally, create the separate Product Category menu in Appearance > Menu with menu items and menu sub-items for mobile menu, as the Mega menu blocks are not supported by mobile
Best Regards