OpenXcom not finding game files

[Noko1]

I downloaded the latest nightliy,
extracted the app image,
created a folder called OpenXcom and moved the extracted files in it,
made the UFO folder and copied the steam version in it.
I ran the executable and it still couldn't find the game. I'm pretty new to this process so please let me know if I'm just being dumb and missed a step. I'm on steam deck desktop mode with KDE plasma. Any help would be appreciated and thank you!