Video in "Made for iPad" apps on macOS

I'm relatively new to Swift development (and native iOS development for that matter)

I've got an iOS app that uses the iPhone / iPad built in cameras, and am looking to make this more compatible with macOS.

Using the normal AVCaptureDevice.DiscoverySession I seem to get the iPhone Continuity Camera and the in-built MacBook Pro camera but I don't see other input devices that I see in QuickTime Player (for example) such as connected external cameras or Virtual Inputs provided by NDI Virtual Input and OBS.

Is there a way to see access these without a specific Mac build (as the rest of the functionality works great, and I'd rather not diverge the codebase too much as it's easier to update one app than two!