If you've already registered, you'll eventually receive a confirmation email from email@example.com. Re-enter your email and the confirmation code to complete your registration.
Didn't get the email?
We've had a lot of problems with bot accounts. As such, all registrations are now completed manually by me, the site owner. This means you may be waiting several days for your email, and even then it may show up in your spam folder.
I'm sorry for the inconvenience! If you feel your registration confirmation may have gotten lost, you can email me at firstname.lastname@example.org with the username you tried to register with and I can go look for the code manually.