If you would like to use mega menu in your marketplace website simply follow below some of instructions.

1. Login to your Dashboard
2. Appearance
3. Menus
4. At first click, the Screen Options button from the top of your page then check CSS Classes

Check below Screenshot-

5. Now go to the Menu structure

6. Click the menu in which menu you would like to add mega menu features then add “has-mega-menu” class in the CSS Classes (optional) field.

7. Don’t forget to “Save Menu”.

7. Now go to Appearance -> Widgets

8. You’ll find a widget area which name “Home – Mega Menu” in here “Home” is your parent menu name.

9. Just Drag & Drop the “Mega Menu Item Widget” in the “Home – Mega Menu” widget area. Now you can add your mega menu link.