Prism Launcher
You can use CreativeMode mods with Prism Launcher.
For the best experience with CreativeMode mods, consider the CreativeMode Launcher.
Setup#
Follow the installation instructions for Prism Launcher from prismlauncher.org/download.
Add an Instance#
Click on the top left button named "Add instance", select your version (1.21.5 or 1.20.1) then scroll down and choose on "Mod Loader" the Fabric option (0.16.14 or latest). Remember that you also need the Fabric API mod.
Add CreativeMode Mods#
Download mods from creativemode.net. Select your new instance and click on "Folder" located on the sidebar. There you can open a folder named "minecraft" and then "mods" (if they doesn't exists, you can manually create them), you can drag and drop your mod files onto the "mods" folder.
Launch#
With your instance selected, click on the sidebar button named "Launch". Minecraft launches with your mods loaded!