To take advantage our Rates feature your Shopify plan must include access to Shopify's Carrier Service API. When using a development store this is included free of charge. The moment you switch to a paid Shopify plan your access will be terminated unless you are using Shopify Plus or Advanced.
There are a couple of ways in which you can get this added to your plan
- Switch your Shopify plan from monthly to annual billing and Shopify will enable the Carrier Servive API free of charge and give you a 10% discount on your overall plan.
- If you are not ready to switch to annual billing, Shopify can add the Carrier Service API to any plan for $20 per month.