Microsoft Teams provides an in-built option for changing the background in meetings. To do so, click the profile avatar icon under your camera view and choose a background image on the right side.
Microsoft adds ... Another Teams capability coming in August will allow administrators to customize Teams panels' appearance by setting custom background images (Feature ID: 402183).
Download the Microsoft Teams app on your desktop. Open the app and click on the more options mw, senu (three dots). Now, select background effects. Now, click on ‘Add new’ and select an image ...