...
Click More Options (…) next to the Team name.
Select Add member.
Enter the guest’s email address. If they have an @hsc address, you can look them up in the Outlook Address book.
If needed, select the pencil icon to edit the guest’s name.
Click Add.
The guest will receive an email from Microsoft Teams with the subject "You have been added as a guest to West Virginia University in Microsoft Teams." Ask guests to check their Junk folder if they don’t see this email.
If a guest doesn’t have a Microsoft account associated with their email address, they will be directed to create one for free.
The invited guest must click Open Microsoft Teams within the invitation to accept it.
Once the guest has accepted the invitation, they will receive an email with an access URL specific to them. Make sure the user saves this URL in their bookmarks for future access. It may take a few hours before the guest has access to the Team.
Team members will see a message in the General channel announcing that a guest has been added.
...