Excuse the detour, you're almost there.

Maybe you are using a Chromium-based browser, or just didn't read the password query completely. This query is used to get rid of spam bots, so unfortunately it is necessary.

Just go back to the previous page, and type modplug in both the user and password field. You can then proceed with creating an account.

Thank you for your patience and sorry for the inconvenience!

Authentication message in Chromium-based browsers