The live transcription is available at moment for “Licenced users”

To Enable it, go your account > Settings, and to section bellow and enable: “Closed captioning” and Enable live transcription service to show transcript on the side panel in-meeting

Closed captioning:
Allow host to type closed captions or assign a participant/third party device to add closed captions
Enable live transcription service to show transcript on the side panel in-meeting

Enabling the live transcription on the Zoom meeting:

Start the meeting
Click CC/Live Transcript button that appears on Zoom toolbar
Click Enable Auto-Transcription