How do I add a user to a team? Can users switch teams?

Only administrators can invite new or existing users to teams.

New users can be added in the ‘Users’ page via the ‘invite new user’ section.

To switch an existing user from one team to another or add them to another team, navigate to the ‘users’ page. Find the user and select ‘Edit’. Once you have edited the users team settings select the ‘Save’ icon once completed.’ 

More information can be found here