No worries: on your dashboard page, go to 'Sign ups' on the left hand menu, then you should see Challenge Sign-ups for [Username], and the 'Edit sign-up' button is there below 'Antonia Forest Fanworks'. Click on it and you'll see a page to edit your prompts, and for each prompt you want to de-anonymize uncheck the box that says 'Semi-anonymous prompt'. Any problems, just let me know.