This article explains how to use external controllers on a Steam Deck. Instructions for all Steam Deck models.
Connect 13 controllers to Steam Deck. Dualsense. Dualshock. Joycons. PowerA
The Steam Deck has built-in, highly customizable controls, but they aren't always the most comfortable for long play sessions. Fortunately, there are other options.
The Steam Deck is compatible with both wired and wireless controllers. You can even connect multiple controllers at once to play on the couch with your friends.
You can use wired or wireless controllers with the Steam Deck: