Note: Only a team's administrator (the user who created the team) can add team members.
From your team’s page, select the Members tab
Click Add Member
Add a user by typing the email address associated with their Cloud account
Notes:
You must enter the full email address
An error will occur if a Cloud account does not exist for the email address
The new team member will receive an email asking them to confirm their membership by clicking a confirmation link
The new team member will be added to the team Members list as soon as the administrator has added their email address but they will not have access to the team's sites. Once their membership is confirmed, the new team member will have access to any sites shared with the team.