This article explains how to open the keyboard on a Steam Deck, including how to open the keyboard in both Game Mode and Desktop Mode.
Steam Deck How to open the keyboard in desktop mode, play games, etc.
Your Steam Deck has a software keyboard that automatically appears when you perform specific actions that require a keyboard, such as clicking the search bar. If you need the keyboard and it hasn't automatically appeared, you can bring it up at any time.
Open a game or app that supports the virtual keyboard.
Hold the STEAM button and then press the X button.
