At the moment, we're able to have only 1 Owner for each license. But after your subscription, you can add Team Admins to your Team so they'll have similar permissions as the Owner.
One of the biggest differences between an Owner and a Team Admin is that only the Owner can manage full billing information. But for the rest, Team Admins can do almost it all. For example, adding and removing people to the team, managing boards, etc.
Note: Team Admins can't move a team board to public, only the Owner.
Click here to learn how to assign Admins to your Team.
Click here to learn more about EasyRetro user roles.