Make Someone a Team Owner in Teams

You may want someone other than you to have team owner privileges.

If you want to make someone an owner or view who's an owner of an existing team, go to the team name and click More options More options button > Manage team.

The Role column tells you if someone is a team member or owner. To make someone an owner, click Member and then select Owner.

You can also make someone a team owner while you're creating a team. When you're adding team members, designate whether each new person is going to be a team member or team owner by clicking Owner under the Member menu.

 

Source: https://support.microsoft.com/en-us/office/make-someone-a-team-owner-09eb80c1-9f3b-4f6c-b6c0-45555d46ee2a