How to Invite Members
On tab 
Members of your Group, Owners may invite new Members by either sharing the Group Code or directly inviting other users to join the Group.
Members of your Group, Owners may invite new Members by either sharing the Group Code or directly inviting other users to join the Group.Share the Group Code
Find the Group Code at the top of tab Members and share it with users you would like to invite to your Group (e.g. send e-mail, write on blackboard, ...).
Members and share it with users you would like to invite to your Group (e.g. send e-mail, write on blackboard, ...). 
Directly invite users
Search for users you would like to invite by entering their e-mail address or GeoGebra username in the provided User Search.
After clicking Invite...
- an invitation e-mail is sent to the invited user.
- the user is being listed on tab
Share the Viewing Link
Owner(s) may access a Viewing Link on the Group Settings Page, which can be sent to other users in order to give them viewing access to the Group.
Note: Users with the Viewing Link do not automatically become Members of the Group and only have viewing permissions.