JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/webrtc-adapter/3.1.0/adapter_no_global.js"></script>

JavaScript

var iceServers = [

] 

var config = {
  iceServers: iceServers,
  iceTransportPolicy: "all",
  rtcpMuxPolicy: 'negotiate'
};
              
var pcConstraints = {};
var offerOptions = {offerToReceiveAudio: true};

pcConstraints.optional = [{'googIPv6': true}]; // Whether we gather IPv6 candidates.

var pc = new RTCPeerConnection(config, pcConstraints);
pc.onicecandidate = iceCallback;
pc.createOffer(
  offerOptions
).then(
  gotDescription,
  error
);

function gotDescription(desc) {
	console.log("OFFER DESC:", desc);
  pc.setLocalDescription(desc);
}

function error() {
	console.log("sth goes wrong", arguments);
}

function iceCallback(event) {
  console.log("ICE!", JSON.stringify(event.candidate));
}