These options allow you to personalize the Related Products & UpSells sections. You can change it to a Tab or List format, change the number of products displayed, etc.
The UpSells section is called "Recommend"
To add products to the UpSells section, please add them to the product management section. You can set this when creating a new product. If the product is already available, please click "Edit" on the product to set this value.
