Step 1: Click edit your page from your creator page:
Step 2: Click about from the top menu and scroll down to the Patreon URL section:
Step 3: You will see a Patreon URL text box where you can enter your preferred URL name and we'll let you know if it's not available with a red line.
Step 4: Don't forget to scroll back up and select save changes!
If the URL you want is already claimed, you'll see red text alerting you that this URL is unavailable.
Patreon custom URLs are claimed on a first come, first served basis. Even if the associated Patreon page seems inactive, Patreon is unable to free up that URL.