When meetings include live captions or transcription, Teams automatically identifies the speaker along with what they say. You can choose to hide your name in live captions, live transcription, and the saved transcription that's available after the meeting.
Do this before the meeting where you want to speak anonymously.
- Select More options
> Settings
in Teams. - In Accessibility > Captions and transcripts, turn off the Automatically identify me in live captions and live transcripts toggle.