This resource pack is meant for Minecraft version 1.18.1.
Click on the latest release and then click on the link EnderFluid.zip.
Unzip the downloaded archive and move the unzipped folder into Your Minecraft folder/resourcepacks.
You can find your Minecraft folder by opening the launcher and clicking on Installations.
Search for an installation and click on the folder icon next to the Play button.
You should now see the EnderFluid resource pack in-game.