Implement xmpp in dart to use in flutter

I want to implement jitsi in flutter application with the use of webRtc. I know that I have to reimplement the xmpp module in dart from lib-jitsi-meet. I am analyzing it for a few days, but I am still confused about connecting it together. From my observations, I would start from the xmpp.js file and then implement all other things that it uses. But then I am not sure what to do. The library for webRtc I want to use has already RTC datachannels and peerconnections, which means that from lib-jitsi-meet I do not need to reimplement the RTC module. The thing that I do not know is where is the listener for the data WebRTC needs. I do not see onMessage listener or sth like that.

In summary, I have 2 questions:

  1. Do I have to implement some other modules besides xmpp?
  2. Where data to establish a connection in WebRtc is listened to?