In order to create a team on your Enterprise account, you must have manager or admin access.
To create a team:
1. Click the People Tab.
2. Click the Teams option.
3. Click the + sign to create a team and give your team a name.
4. Add members to your team.
Once you've created your team, any contributor, manager or admin can add the team to a project.
To add a team to a prototype:
1. After you've created a prototype, click the green circle with the people and "+" icons at the top right of the prototype dashboard.
2. Add a team(s) to the prototype for access. This access granting must be done on a per-prototype basis. Any members added/removed from the team will also be reflected on relevant prototypes (e.g. if you remove a member from a team they will lose access to the prototype).