Play audio file if outside line is busy

If an outside line (not to an extension on the local network) is busy, Freepbx automatically disconnects/ends the call. Is it possible to add a small audio file telling my employees that the line is busy? If yes, how can i do this in the GUI?

There are options under Settings, Route Congestion Messages, does one of those do what you are looking for?

Thanks for your quick reply… i dont see the option when the outside line is busy…