1. Open workspace administration.
2. Select the Team section. ( pic. 1)
3. Choose a team where you need add new members and click on the Edit icon on the right side of your screen. (pic. 2)
4. Select Mass import from list. (pic. 3)
5. Add the e-mail addresses. You can paste list of e-mails from excel. Put each email on a separate line. (pic. 4)