Go to Products > Categories (Level 1) > WeltPixel Mega Menu

You will be able to configure a different display mode for each category:

1. Menu display mode for each level 1 category: Full Width / Sectioned / Boxed / Default Magento
2. Number of columns for each category menu
3. Width of the columns

Go to Products > Categories (any) > WeltPixel Options

1. Custom Link - set a custom link for any category in the menu
2. Open in new tab - opens the custom link/category page in new tab