Recommended products are configured in the administrative panel of the project. They must be added for each catalog product in the Products section.
In the window that opens, find the Related products field and start typing the name of those products that should be displayed in the product card, then select the necessary ones in the drop-down menu.
If you specify more than 4 products, then in the list of recommended items you will be able to scroll through the list.
After making changes, click Save.