If you signed up via the website, please make sure that you've followed the instructions on checkout and connected your Discord account to your customer account. You can only have one Discord account connected at a time.
To connect your Discord account, log into your customer account and click the Discord tab. You may find detailed instructions on the Discord Connect page of the website.
If you are a user migrating from a previous payment platform e.g. Mee6, Patreon, etc. please make sure you cancel your subscription on the 3rd party platform and then try connecting your Discord account through your account profile here.