To pair a package that you have already bought with a specific product or all the products you are selling in your store. Visit PRODUCTS>PACKAGING, select the correct item and click on the MANAGE button.
Select the specific customization of that package and click on settings.
Click on CONNECT NEW PRODUCTS.
if you want to ship all your parcels with that packaging select USE FOR EVERY PRODUCT;
if you want to pair this packaging only with some specific products, select between public products and private products.
Find the item you want to pair and click on the plus button for your own items.