How to get Primary Contact ID from Incident via REST API

Summary:

I need to retrieve the primary contact's ID from the Incident table, but cannot find the correct ROQL syntax

Content (required):

I need to retrieve the primary contact's ID from the Incident table, but cannot find the correct ROQL syntax. IT HAS TO BE VIA REST API, not PHP connect

https://xxxxxxxx.org/services/rest/connect/latest/queryResults?query=select Id, category, PrimaryContact.ID from incidents where createdtime>'2021-11-01'

Version (include the version you are using, if applicable):

Code Snippet (add any code snippets that support your topic, if applicable):

https://xxxxxxxx.org/services/rest/connect/latest/queryResults?query=select