Load Appcues asynchronously in a wrapped method.

example.html

<script>
  (function(a, ns, cb) {
    window[ns] = function(callback) {
      (window[ns].q = window[ns].q || []).push(callback);

      if (window[a] != null) {
        while (window[ns].q.length) {
          cb = window[ns].q.shift();
          if (typeof cb === 'function') cb();
        }
      }
    };
  })('Appcues', 'AppcuesReady');
</script>

<script>
  // You could then use Appcues immediately by calling Appcues.ready() with a callback:
  AppcuesReady(function() {
    Appcues.identify('userId', {email: '[email protected]'});
  });
</script>

<!-- Load the script at any time later -->
<script src="//fast.appcues.com/23.js" async defer onload="AppcuesReady()">