Getting Origin setup on the steam deck requires you to find a download for it on another site than the official one because the download button is glitched and simply does not show up. After you find and install Origin, you have to add it's exe as a non-steam game, and from there you boot it up from steam and install the game and play it from there. You will need to use the touchscreen to full-screen the Origin window after launching it, as well as when you want to launch the game.