Attendees at the event should be reminded at the beginning of the event that it will be recorded. This is most usually done immediately after the Acknowledgement of Country.
The suggested wording to include in the introductory words is:
This public lecture/event/symposium/ will be recorded. The recording will be made available after the event. Participants will be able to ask questions/make comments via (chat or other functions if event is conducted online). If you do not wish your question or comment to be in the recording please contact XXX after the event. (Alternatively please ask your question/make your comment to the presenter after the event through EMAIL ADDRESS).
For online events, the event organiser may wish to display a recording disclaimer to participants before a recording starts.
Note: if questions are asked via "chat" in Zoom or "conversation" in teams, they will not be included in the recording, however event organisers may be able to save in-meeting chat transcripts.
You may find it useful to have a moderator dedicated to reading out the questions.