Hi as far as I know the ux2 isn’t class compliant so it won’t work with iOS.
may this juncture it barely works on macOS due to a long over due lack of driver updates.
I’d recommend an Irig hd2 if you just want a guitar interface for iOS as line 6 has had since November of last year to get their drivers in line for Big Sur and apparently just refuses to do so, as far as I’m concerned they are no longer apple friendly.
hope this helps.