If you are using the Chrome web browser, you can enable captions in the Chrome web browser on your computer/phone, see this link from Google. (This has been supported in Chrome since 2021.)
If Zoom is being used, Zoom supports live transcription in its application (if you are using a new enough version). (Ask for it to be enabled in that Zoom session.)
If BigBlueButton (BBB) is being used, BBB does not currently support automatic live transcription.