If you have your students' email addresses to hand, you can invite them directly.
1. Open your classroom from the sidebar and go to the Students tab.
2. Click Add students.
3. Choose Enter email addresses, then click Next.
4. Paste your students' email addresses into the Email addresses box. You can separate them with commas, spaces or semicolons, so a list copied out of a spreadsheet usually works as is.
5. Send the invitations. Invited students show under the Invited tab until they accept.