Yes! You should ask students to register themselves by clicking on the “Register” button. They can then authenticate by using a Google account (or Schoology account) or create a new username and password. As part of the registration process they will be asked for a class word. This will put them on the roster for that class.
Detailed instructions about this are in the help document for using the portal. You can find a link for that on the home page of the portal or by clicking the “Help” link once you have logged into the portal. Here is a direct link to the manual: https://ngss-assessment-resources.concord.org/NGSAGuideTeachers.pdf