JSFiddle - React, Tailwind, and code Playground

HTML

Browser SDP <br />
<textarea id="localSessionDescription" readonly="true"></textarea>
<br />
<button onclick="window.copySDP()">
  Copy browser SDP to clipboard
</button>

<br />
<br />
<br />

Application SDP<br />
<textarea id="remoteSessionDescription"></textarea> <br />
<button onclick="window.startSession()"> Start Session </button><br />

<br />

Video<br />
<div id="remoteVideos"></div> <br />

Logs<br />
<div id="div"></div>

CSS

textarea {
    width: 500px;
    min-height: 75px;
}

JavaScript

/* eslint-env browser */

let pc = new RTCPeerConnection({
  iceServers: [{
    urls: 'stun:stun.l.google.com:19302'
  }]
})
let log = msg => {
  document.getElementById('div').innerHTML += msg + '<br>'
}

pc.ontrack = function(event) {
  var el = document.createElement(event.track.kind)
  el.srcObject = event.streams[0]
  el.autoplay = true
  el.controls = true

  document.getElementById('remoteVideos').appendChild(el)
}

pc.oniceconnectionstatechange = e => log(pc.iceConnectionState)
pc.onicecandidate = event => {
  if (event.candidate === null) {
    document.getElementById('localSessionDescription').value = btoa(JSON.stringify(pc.localDescription))
  }
}

// Offer to receive 1 audio, and 1 video track
pc.addTransceiver('video', {
  'direction': 'sendrecv'
})
pc.addTransceiver('audio', {
  'direction': 'sendrecv'
})

pc.createOffer().then(d => pc.setLocalDescription(d)).catch(log)

window.startSession = () => {
  let sd = document.getElementById('remoteSessionDescription').value
  if (sd === '') {
    return alert('Session Description must not be empty')
  }

  try {
    pc.setRemoteDescription(new RTCSessionDescription(JSON.parse(atob(sd))))
  } catch (e) {
    alert(e)
  }
}

window.copySDP = () => {
  let browserSDP = document.getElementById('localSessionDescription')

  browserSDP.focus();
  browserSDP.select();

  try {
    var successful = document.execCommand('copy');
    var msg = successful ? 'successful' : 'unsuccessful';
    log('Copying SDP was ' + msg);
  } catch (err) {
    log('Oops, unable to copy SDP ' + err);
  }
}