Requirements to use Carrier Service API
For stores that meet one of the following requirements, you can use the Carrier Service API directly:
It is on the Advanced Shopify plan or higher.
It is on the Shopify plan with yearly billing.
Steps to enable carrier service API
Pleased contact Shopify support. They will assist you with the setup necessary for your store.
Visit Shopify Help Center.
Open up chat widget and type in
Hello, how can I enable carrier service api for my store
Click button "Chat with a Support Advisor"