Yes, it is possible.
Please register using one of the methods in the related links.
Related:
Add multiple users at once using CSV file (Web Browser)
Invite/Add Users to Group without Email Address (Web Browser)
※If you want to invite 6 or more people, please repeat the operation multiple times or use CSV to invite them.
Notes on not registering an E-Mail Address
- Users will not be able to receive e-mail notifications, including the e-mail containing the initial Login information for Teachme Biz.
The Administrator should inform the account users of their Account name and Password by some other means. - If users forget their login Password, they will not be able to change or Reset it themselves, and will need to ask the Administrator to do so.
- Users will not be able to receive any system notification e-mails from Teachme Biz.
Related: Please provide a list of system notification e-mails sent from Teachme Biz - Users cannot become administrators such as Group administrator or Folder administrator.
If you wish to receive notifications without registering an E-Mail Address
Please consider using "Information on Updates" or "Push Notifications" in the mobile app.
However, the information notified via the mobile app is limited.
For details, please refer to the related articles here.
Related:
What methods are available for receiving notifications?
In what situations will notifications be sent to mobile devices (smartphones, tablets)?