Fetching values for CMDB-based custom fields in Jira REST API

Hi there.

I’m trying to fetch valid custom field values for a custom field with type/schema com.atlassian.jira.plugins.cmdb:cmdb-object-cftype (as indicated by the “create meta” api). The response also gives me an autocomplete url for the field. However, whereas most fields’ autocomplete urls are pointed to api.atlassian.net, this one is not and is pointed to our atlassian domain. Further, using our apps oauth bearer token yields a variety of errors depending on how specifically the request is made. The url is of the form https://<our atlassian doamin>/rest/servicedesk/cmdb/<an id>/field/customfield_<field id>/config/<some other id>/autocomplete?.

What is the proper way to fetch valid values for this field via an api? How does such a request need to be authenticated?

Any help or hints that anybody has would be appreciated.