test.html

<script src="https://samanco.kakaocorp.com/uploader/widget/waveuploader.widget.js"></script>

<script>
  WaveUploader.init({
    appKey: '59705d2977c86a9d4d1ba044',
    cpKey: 'test',
    userKey: 'test',
    onError: function(){
    },
    onAdd: function(data) {


      debugger;

    }
  });

  document.getElementById('btn').addEventListener('click', function() {
    WaveUploader.open();
  });
</script>