To invite a new member in a WorkGroup, you select to view a WorkGroup and click on "Invite People" which is above the list of pictures of its members. You will need to fill in the email address of the new member and if this member is not a user of the platform, a new user will be created and notified via email. It is possible not always to see the "Invite People" link because you might not have the permission for the specific WorkGroup.
Referral Generation & Collaboration Platform