For anyone that wants to know how I just sorted this and can now add PS1 and PS2 games.
Basically I am trying to set up LaunchBox for Xbox Series X. All of my emulators are installed as UWP on the Xbox itself.
This link explains how to install LaunchBox and emulators and most of the info is fine. RetroPass/Docs/SetupDuckStation.md at main · retropassdev/RetroPass · GitHub
However, in the case of DuckStation and XBSX2 It says that the application path to the emulator does not have to point to the real application. This approach seems to be fine for N64 games, Dreamcast games, Genesis etc. But does not work for PlayStation or PlayStation 2 games.
If I don't put the real application path in LaunchBox for DuckStation/XBSX2 PS1 and PS2 games will crash when trying to import them.
Slightly awkward as the real app paths to my emulators are not accessible by Launchbox as they are on my internal Xbox drive.
What works is that if you download the PC versions of DuckStation and PSX2, go through the set up process with your bios files. Then go into Launchbox, set up your emulators and select the app path to the emulator of the one installed on your PC even if this will be wrong when you are playing on the Xbox. It will then let you import your games and you can go back to the Xbox, launch something like Retro Pass with Launchbox and your PlayStation games will load up the version of DuckStation/XBSX2 that you have internally on the Xbox.