Unless the chat program supports audio broadcasting (very unlikely - I am not aware of any programs that do this - they tend to be designed for text and media transmission on a person to person based system) there isn’t going to be anyway to do what you want unless you host a broadcast stream that you could provide a link to for others to listen to. You might be able to use more of a meeting like platform like gotomeeting which can do things, but you would probably have to share more than just audio and is probably be more work than you are looking for.