title: Recurly.js in sandboxmode - ThreeDSecure not returning anything after clicking "Succeed Test Authentication"
body: <p>I have problem with implementation of 3ds verification for Recurly, i have followed example from <a href="https://github.com/recurly/recurly-js-examples/blob/master/public/3d-secure/authenticate.html" rel="nofollow noreferrer">https://github.com/recurly/recurly-js-examples/blob/master/public/3d-secure/authenticate.html</a></p>
  
  <p>My problem is that first iframe is loading correctly, but after clicking "
  Succeed Test Authentication" returns nothing to my threeDSecure.on('token' funcition(){}). It loads iframe with information "To complete your checkout process, please close this browser tab and return to your checkout form." Thanks for any responses.</p>
  
  <p>My view file
  <a href="https://pastebin.com/irCuGr48" rel="nofollow noreferrer">https://pastebin.com/irCuGr48</a></p>
  
  <pre><code>&lt;form id="pm-recurly-form-3ds" method="post" action="&lt;?php echo esc_url( get_permalink( get_queried_object_id() ) ); ?&gt;subscription/pay/"&gt;
              &lt;div id="container-3ds-authentication" class="three-d-secure-auth-container col-12 " &gt;&lt;/div&gt;
              &lt;div class="three-d-secure-submitting-messagge col-12"&gt;
              Authenticating your payment method...
              &lt;/div&gt;
              &lt;?php wp_nonce_field( 'pm-register-subscription-nonce' ); ?&gt;
              &lt;input type="hidden" name="pm-form-request" value="register-subscription" /&gt;
              &lt;input type="hidden" name="pm-price-plan" value="&lt;?php echo esc_attr( $pm_price_plan ); ?&gt;"&gt;
              &lt;input type="hidden" name="three-d-secure-token" id="three-d-secure-token" value=""&gt;
              &lt;input type="hidden" name="recurly-token" id="recurly-token" value=""&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>My JS file
  <a href="https://pastebin.com/7zYDAEJs" rel="nofollow noreferrer">https://pastebin.com/7zYDAEJs</a></p>
  
  <pre><code>// We expect this page to load with the following parameter pattern
  // `/3d-secure.html#token_id=xxx&amp;action_token_id`
  // This is a simple parser for that pattern. You may use window.URLSearchParams
  // instead if IE11 support is not needed
  var hashParams = location.hash.substr(1).split('&amp;#038;').reduce(function (acc, i) {
    var [k,v] = i.split('=');
    acc[k]=v;
    return acc;
  }, {});
  // Configure Recurly.js
  recurly.configure(recurly_key);
  // In order to remain backend agnostic, this example passes the Recurly.js credit card token
  // to this page via the URL hash. Here we add it to the form so that it will be passed
  // to our backend
  document.querySelector('#recurly-token').setAttribute('value',hashParams.token_id);
  
  // Now we construct the 3-D Secure authentication flow
  
  var risk = recurly.Risk();
  var threeDSecure = risk.ThreeDSecure({ actionTokenId: hashParams.action_token_id });
  var container = document.querySelector('#container-3ds-authentication');
  
  
  // Handle errors that occur during 3-D Secure authentication
  threeDSecure.on('error', error);
  // 'token' is called when your user completes the 3-D Secure authentication flow
  threeDSecure.on('token', function (token) {
      console.log(token);
      // place the result token in your form so that it will be submitted
      // when the customer re-submits
      document.querySelector('#three-d-secure-token').setAttribute('value',token.id);
      // Hide the container once we have a token
      container.style.display = "none";
      // Show the loading message
      document.querySelector('.three-d-secure-submitting-messagge').style.display = "block";
      // submit the form automatically
      recurly_form_verify.submit();
      });
  
      // Attach our 3D Secure session to the container
      threeDSecure.attach(container);
      // Show the container
  
      container.style.display = "block";
    // runs some simple animations for the page
    document.querySelector('body').classList.add( 'show' );
  </code></pre>
  
  <p>Second iframe</p>
  
  <p><a href="https://i.stack.imgur.com/Wmka1.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Wmka1.png" alt="enter image description here"></a></p>