You can set the Roles & Permissions for your team members in the Permissions tab for your team. If your team is part of an enterprise, you'll set these for every team at the enterprise level.
Instructions
Click the Account icon in the top-right corner of your window, to open the Me-menu.
Locate the My Teams option, and click it.
Now you're in the Team Panel. Locate the Permissions tab, and open it.
You can toggle permissions for Members, Administrators, or team Owners.
Related article
In the Manage Team Members & Permissions article, you'll find an overview of all permissions.