Does the connection to the Sage HR Suite API also work via NT authentication?

No, a second entry must be created in the IIS with the same physical path as follows:

Copy the physical path of the existing application:

A new application with the same path and a different name is then created and set to Anonymous:

Now, instead of the original API URL “http://<IP or server name>/HRPortalApi ”, the new endpoint can be used  " http://