src/popup.html

<!doctype html>
<html>
<head>
  <meta charset="utf-8">
  <meta http-equiv="Cache-Control" content="IE=edge">
  <meta http-equiv="Pragma" content="no-cache">
  <meta http-equiv="Expires" content="Sat, 01 Jan 2000 00:00:00 GMT">
  <title>RingCentral RingCX Embeddable</title>
  <meta name="description" content="RingCentral RingCX Embeddable">
  <meta
    name="viewport"
    content="width=device-width, initial-scale=1, user-scalable=0, maximum-scale=1, minimum-scale=1"
  >
  <style>
    html {
      margin: 0;
      padding: 0;
      width: 100%;
      height: 100%;
    }
    body {
      margin: 0;
      padding: 0;
      width: 100%;
      height: 100%;
      overflow: hidden;
    }
    #appLoading {
      text-align: center;
      padding-top: 30px;
    }
    #engage-voice-embeddable {
      left: 0!important;
      top: 0!important;
    }
    #engage-voice-embeddable header {
      cursor: default;
    }
    #engage-voice-embeddable div[class*="button"] {
      display: none;
    }
  </style>
</head>
<body>
  <div id='viewport'>
    <p id="appLoading">
      Loading...
    </p>
  </div>
  <script>
    window.__ON_RC_POPUP_WINDOW = 1;
  </script>
  <script src="./adapter.js"></script>
</body>
</html>