Retaining List of Non-Promoted People on a Zoom Webinar

During our webinars, we have members of the public join for comment.  Is there a way to capture their personal information (name and phone number) in case we need to follow up with them post meeting?  These folks are non-promoted and usually only show a nickname, shortened name, or last 4 digits of a phone number.  Is it possible to collect their information without asking them for it?

Any help would be greatly appreciated!