Here are the steps you need to follow to change your background image in a Teams meeting:

1. Open your Teams meeting and select ‘More actions’ from the lower left side of the window.
2. Click on ‘Show Background Effects’ and select ‘I have a background image’.
3. Upload or choose the image you would like to show as your background image during the Teams meeting.
4. Click on ‘Apply’ to apply the change and save your selection.