Use Shipping Rest Api for connecting with external parties

To handle the Shipping Functionality with included Rest Api, it is necessary to enable this. 

Go to Shipping Manager Setup, go to "Detailed App Setup" 

Enable the feature "Connect via Rest Api". 

See more about the API in Shipping Manager here: https://abakion.zendesk.com/hc/en-us/articles/9362318957212-API-for-Shipping-Manager