If you are an Admin or an Account Manager on an account, you can set existing Team Members or Team Managers as an Account Manager to be able to create teams.
First, go to Account Settings, and then click User Management.
From here, you can either Sort by the name and scroll, or use the search on the right.
Once you click on their name, the right bar displays all of the teams they're currently on and their account status. Click on the arrow below their name and change their status to Account Manager.
Now they have the ability to create teams and manage other teams.