Offical Launcher Guide
By: Finazon
Before starting, I'd recommend using Prism Laucnher instead, as it is easier to set up modded versions of Minecraft. If you still wish to use the offical launcher, follow the steps below.
Step 1: Install Fabric for Version 1.21.5 (more detail will be added later).
Click Here for the Fabric Launcer
Step 2: On Windows, run the Windows Button + R, then type in '%appdata%'. Click minecraft then create a new folder called 'mods'.
Step 3: Drag the mods.zip (from the main page) folder into the instance's mods folder and extract it. If the extaction created a new folder, move all the mods out of that folder and into the instance's mod folder. It should look like the below image.
Congrats! You have installed all the mods required to play on the server. If you wish to add clientside QoL mods, go ahead. When you are ready to play open minecraft and use the IP on the main page.