Visit the Cfx.re Portal to subscribe to Element Club. You'll need to select a tier:

Subscribe to a tier that explicitly includes custom clothing streaming. The minimum required tier is typically the level. Higher tiers (Aurum, Platinum) offer more player slots but provide the same clothing streaming capabilities. Step 2: Link Patreon to FiveM Keymaster

Fill out the form with your server’s label, the public IP address of your server hosting machine, and the server provider type. Click .

The "FiveM EUP Key" is almost exclusively associated with the that controls these advanced packs.