a button that starts a new video call

button-and-iframe.js

<button onclick="startCall()">
  start call
</button>

<script>
  async function startCall() {
    let callUrl = 'https://api-demo.daily.co/this-is-a-placeholder',
        iframeEl = document.createElement('iframe');
    iframeEl.width = 350;
    iframeEl.height = 425;
    iframeEl.style.position = 'absolute';
    iframeEl.style.right = '1em';
    iframeEl.style.bottom = '3em';
    iframeEl.src = callUrl;
    iframeEl.allow="camera; microphone; autoplay";
    document.body.appendChild(iframeEl);
  }
</script>