With Groovy menu you can add any content to the menu dropdowns (including mega menu), using various Page builders. The full list of supported Page Builders can be found here.

Note. To use with WPBaket Page Builder for menu blocks you should first enable WPBakery for Menu Blocks.
How to create Menu Blocks
To create a menu block please navigate to Groovy menu > Menu Blocks
and click on Add New Menu block
button
Note. Depending on the page builder you are using you will see different Menu block single page reflecting the interface of the builder. If you see a classic text editor or Gutenberg editor but expecting to see the different page builder interface, for example, WPBakery Page builder, make sure that the one is enabled for Menu blocks post type from builder settings.
How to add Menu Blocks to the Navigation menu
To add a menu block to the Navigation menu navigate to Appearance > Menus
and select a block from Menu blocks
Note. If you don't see Menu blocks tab please check if the appropriate checkbox is checked in Screen Options