The issue here was in fact the endpoint. Instead of https://api.businesscentral.dynamics.com/v2.0/<user-domain-name>/api/Contoso/Punchout/v2.0/companies(<company-id>)/<EntityName>, it is https://api.businesscentral.dynamics.com/v2.0/<tenant id>/<environment name>/api/<Api publisher>/<Api group>/v2.0/companies(<company ID>)/<EntitySetName> . If after this you receive a 403 forbidden error, simply generate a permission set within vs code that gives your add-on application full control over its tables/pages/data etc and go into the BC UI and search entra -> microsoft entra application -> select the application you are working on -> under permission sets, add the one you just created in vs code.