Who turned on transcript function?

Welcome to the Zoom Community, @DusicaM.

Sorry, but that level of detail is not available.

Not sure what you're worried about, it doesn't cost you any extra if it's on versus off.  If you just don't want anyone using it because "someone having a transcription is a bad thing", just disable it.

If you want to disable transcription for your own meetings only (not for the whole account), you can do this in your personal settings:

1. Sign in to the Zoom web portal.
2. Click Settings in the navigation menu.
3. Under the Meeting tab, scroll to In Meeting (Advanced).
4. Toggle off Automated captions and Full transcript.

This will prevent the transcription feature from being available in your meetings. For more details, see: Using live transcription in meetings[1].

@DusicaM 
In addition you can also limit the users that can enable captions to host or co-host, by ticking the "Allow only the following users to enable captions for the meeting or webinar" check-box.