title: Django: Channels and Web Socket, how to make group chats exclusive
body: <p>Eg i have a chat application,</p>
  <p>however, i realised that  for my application, as long as you have the link to the chat, you can enter. how do I prevent that, and make it such that only members of the group chat can access the chat. Something like password protected the url to the chat, or perhaps something like whatsapp. Does anyone have any suggestion and reference material as to how I should build this and implement the function? Thank you!</p>