We just need to update the details of the team.
Login, find your team, and look at the About section. You'll see something like the following screen;
Press the little pencil icon on the left ( near the word About ) and these details go into edit mode.
On the edit screen - towards the bottom you'll see your role, and some toggle options to change.
In the example above - I've switched my role to Both Manager and Coach - why not!
Hit the Save button and your new role is established. You can see that updated as below.