I suggest you don’t. SteamOS is different to other Linux distros in that it’s read only, so installing a driver requires making the filesystem read-write which is a straight road to messing up your install if you don't know what you’re doing, plus every update will delete your changes.

Stick to what you can install with flatpak on the Steam Deck. You can also just install Mint or Ubuntu on a regular computer you might have and try stuff there.