Do you mean xcb instead of xkb?
I found that the qt.qpa.plugin: Could not load the Qt platform plugin "xcb" error was a symptom of missing libraries as described here: Options for packaging a complex (py)QT application: ChimeraX
I think the solution offered in the linked thread can be revived by installing steam-run with an additional switch as described here: Numerous Steam games failing with missing libcrypt.so.1 - #3 by raphi
I tried, but failed so far…