This article explains how to change your background in Microsoft Teams before and during a meeting.
How to change your background in Microsoft Teams, a demo tutorial
MS Teams backgrounds can help you hold meetings anywhere. They remove the distractions of what’s happening behind your shoulder, help your team members focus, and allow you to look professional.
Open Microsoft Teams. Select the Camera icon for a new meeting or choose one of the meetings under Recent.
Give a new meeting a name. Select Get a link to share or Start meeting. Share the meeting link via email or other medium.