Audio outputs to audio interface

Hi All - I'm new to FCP 10.5.1. My system is Mac OS 10.15.7 running on a 'trash can' Mac. I would like to change the default audio outputs of FCP (the first 2) to others on my interface. My interface is set in the Mac System Preferences and in Audio Midi Setup - both of which require any settings to be made by the interface's software.
All sorts of professional audio software applications (ie. Digital Performer, Wavelab etc) allow access to the interface's audio output prefs. I know that earlier versions of FCP had a 'settings' tab that you could use to select your interface and its outputs - but for the life of me, I cannot find anything in FCP 10.5.1! Thanks for any help you could provide.

For audio only, the FCP audio can go out via the system setting - but that will mean you will get all the Mac audio such as warning sounds etc going through. There is a preference in FCP for audio out in Playback/AV output that you can toggle for your audio device, then make sure you have the AV output toggled on in the Window menu

I have found over the past 9 years in my own experiences that audio only hardware interfaces I've used are not recognized by FCP, only video interfaces. Audio only hardware interfaces in FCP can only be controlled via System Preferences.