s3_uploader.js

$(document).on('page:update', function(){
  $('#s3-uploader').fileupload();
  $('#s3-uploader').fileupload(
    'option',
    {
      // Send the request via PUT, rather than POST
      type: 'put',
      done: function (e, data) {
        $(function () {
          $.each(data.files, function (index, file) {
            // retrieve the url of the newly uploaded attachment
            var document_version_id = data._response.result.url;
            // set the value of the s3_url hidden field to the url of the newly uploaded attachment
            $("#s3_url").val(document_version_id);
          });
        });
        return $("#territory-submit").prop('disabled', false);
      },
      start: function() {
          return $("#territory-submit").prop('disabled', true);
        },
      stop: function() {
        return $("#territory-submit").prop('disabled', false);
      },

    }
  );
});

s3form.html

<form id="s3-uploader" data-callback-url="null" data-callback-method="POST" data-callback-param="file" enctype="multipart/form-data" action="https://s3-direct.powerhrg.com/nitro-devbox/" accept-charset="UTF-8" method="post"><input name="utf8" type="hidden" value="&#x2713;" />
  <input type="hidden" name="key" id="key" value="greg_local_test{timestamp}-{unique_id}-b3f955bab1c9bec7d1aadeee5e802635/${filename}" />
  <input type="hidden" name="acl" id="acl" value="public-read" /><input type="hidden" name="AWSAccessKeyId" id="AWSAccessKeyId" value="GWNQSVNDSVYEMTU6EFPD" />
  <input type="hidden" name="policy" id="policy" value="eyJleHBpcmF0aW9uIjoiMjAxNy0wOC0yOFQyMjo0MzowNloiLCJjb25kaXRpb25zIjpbWyJzdGFydHMtd2l0aCIsIiR1dGY4IiwiIl0sWyJzdGFydHMtd2l0aCIsIiRrZXkiLCJncmVnX2xvY2FsX3Rlc3QiXSxbInN0YXJ0cy13aXRoIiwiJHgtcmVxdWVzdGVkLXdpdGgiLCIiXSxbImNvbnRlbnQtbGVuZ3RoLXJhbmdlIiwwLDUyNDI4ODAwMF0sWyJzdGFydHMtd2l0aCIsIiRjb250ZW50LXR5cGUiLCIiXSx7ImJ1Y2tldCI6Im5pdHJvLWRldmJveCJ9LHsiYWNsIjoicHVibGljLXJlYWQifSx7InN1Y2Nlc3NfYWN0aW9uX3N0YXR1cyI6IjIwMSJ9XX0=" /><input type="hidden" name="signature" id="signature" value="eIfe80K0wbI57/T845rvgJ04qio=" />
  <input type="hidden" name="success_action_status" id="success_action_status" value="201" />
  <input type="hidden" name="X-Requested-With" id="X-Requested-With" value="xhr" />
  <input type="file" name="file" id="file" />
</form>