Creating a module
Related items option is part of a DJ-Catalog2 Items module, which allows you to display the products that are related to the currently displayed product in a module position.
To enable this option, let's create a new DJ-Catalog2 Items module just for that. To do so, navigate to Content -> Site modules -> New. Select "DJ-Catalog2 Items".
Name the module and make sure to set "Only related products" to "Yes".
