How to implement connection waiting in WebRTC?

Question

JavaScript

I create a private video chat. It is necessary that the user enter the chat using the generated link and immediately try to establish a connection with the interlocutor without pressing any buttons, if the interlocutor has not yet entered, then he sees only a window with his small video, as soon as the interlocutor entered they should see each other.
On all the examples that I found, there is always a call by ID, without waiting

Answer 1

those examples that I saw - create a room that you can enter by id (room id)
i.e. offer is sent to the server and a connection is expected, or only media is requested, and when connected, the offer is transmitted through the server

Answer 2

https://apprtc.appspot.com/