To assign products in your Shopify store to the Gelato shipping profiles please follow the steps described below:
Access the Gelato shipping profiles from your Shopify account by clicking on Settings > Delivery and shipping > App shipping profiles.
Link the product to the right profile (e.g. let's say you want to connect an 11oz mug to Gelato's shipping profile).
You need to find the relevant Gelato profile (Gelato: Mugs) and then click on Manage rates.
On the next page click on Manage Products.
The window with products will pop up. If you do not see the item in question, you can search for it in the search bar.
Select the products that shall be connected to this profile and save changes.
After this is done, the product will be assigned to the selected shipping profile.