Its literally just the word uinput.

So you can do

sudo echo 'uinput' > /etc/modules-load.d/uinput.conf

Which just tells your system to load the uinput module on startup.

Just to tag on to this, I only needed to enable the uinput module to fix my issue (steam suddenly stopped seeing my 8BitDo controller when it previously could). Didn’t have to do anything with udev rules.

I’ve got an 8BitDo controller and while individual application support varies in quality (had some weirdness with Dolphin not playing nice), Steam consistently recognizes it just fine, literally plug n play. Any standard remappings I would typically do through Steam.

I’d used mine for a few years without issue, but recently had a thing where the controller stopped talking to the dongle. The only way i could use it was if i plugged it in. That required a windows executable to fix unfortunately, but the dongle does work again now. And to your point, I needed windows to remap the paddles on the back, but not the standard buttons.