Enter your school email address into the username field (see below).
For students, your school email address is your email@example.com. You must use your official firstname and lastname, no nicknames. This would be the same username you use to login to the school computer with an "@student39.org" at the end. Example: firstname.lastname@example.org
If prompted for a username and password again, use your school email address (see example above) and your school computer password.