MegaMenu

Start by adding the files listed in the installation zip that was provided when you made the purchase.

Then go into the Shopify admin and open the menu you wish to edit (often "Main menu").

Make sure your menu is listed in this format

To find the image link, so into your shopify admin, and into the settings area where you find files

then copy the link provided on the far right

In your theme editor, click on the header section of your theme

Scroll down to where you see "desktop menu type" and choose from the drop-down option "mega menu"