Shipping rates are automatically built in with the Printify plugin.
Upon downloading the Printify plugin in WooCommerce, activate shipping rate calculation for Printify products in the following way:
1. If you have an Advanced/Annual Shopify plan or carrier calculated rates available for your Shopify account, you can enable Printify Shipping Calculator for Shopify checkouts in My Store > Settings > Shipping Calculator.
2. If you have a Basic or regular Shopify plan, you have to choose between flat rate and weight based shipping settings. Flat rates are applied as a fixed shipping rate to the total order value. Weight based shipping rate considers package weight when setting shipping rate.