There are three ways to play multiplayer in "Minecraft: Java Edition:" through an online server, a LAN server, or a "Minecraft Realms" server.

First, launch up Minecraft Java Edition via the Minecraft Launcher. Once you’ve done this, locate the Installations tab at the top. Click this to open a different panel.

Run Minecraft Java on your Steam Deck with my straightforward step-by-step guide, using Prism Launcher to keep things simple.

Lunar client is a PvP client for Minecraft that includes several optimizations to make the game run more smoothly. Players can download and install it for free.