Requested channel name (for channel join request)
S This expression returns the requested name of the channel that a client wants to join, in a Channel > On join request event.
Note that changing the channel name during a channel join request, using the On interactive condition > Change channel name (for channel join request) action, will cause this expression to return the changed name from then on.
This expression will be blank during a Channel > On leave request event; instead, use the Channel > Name expression.