I have another department logging onto a server without authorization. I want to determine if they added a feature without following the proper procedure.
You can use Event Viewer for this. Open Event Viewer, then expand Windows Logs, and click on Setup.
You'll want to create a filter that looks for these keywords: Microsoft-Windows-ServerManager or just ServerManager or Event IDs 1611 & 1610. Preferably filtering for the event IDs.
For Roles, look for event ID 1611 For Features, look for event ID 1610
Example of Features added screenshot in the Event Viewer on my lab server: