Run the Fabric installer. Select "Minecraft version 1.21.4" and your game directory. Click "Install". This creates a new "fabric-loader-1.21.4" profile in your Minecraft launcher.
Would you like help checking if this specific file is safe or how to install it? File name- Fullbright-Mod-Fabric-1.21.4.jar
: A common library that almost all Fabric mods require to function correctly. Run the Fabric installer
: Provides clean on-screen feedback when the effect is enabled or disabled. File name- Fullbright-Mod-Fabric-1.21.4.jar