OBS plugin for Vulkan/OpenGL game capture on Linux. It works with 64bit games.
If You want to add 32bit games support, install obs-vkcapture-32bit package

to use it, right click game on steam -> properties, as launch options type
obs-gamecapture %command%

To enable game capture globally, type
export OBS_VKCAPTURE=1
at the end of the /etc/profile.local file