Sprout plugin: Send information in AJAX success response

Question

I'm using Sprout for registering to events, I want to be able to send a code in the AJAX response when EVENT_AFTER_SAVE occurs. At the moment, I get {success: true} back, but I want to be able to get {success: true, code: "XXXXX"} after save

The code will be coming from a Channel called Tokens, which consists of one field: tokenCode. I want to grab one at random and send tokenCode as "code"

This is what I want my AJAX request to be, note var redirect = '' + data.token

$('#token-form').submit(function(event) {
  event.preventDefault();
  // prepare some variables
  var postUrl = 'sprout-forms/entries/save-entry';
  var formData = $(this).serialize();

// process the form
  $.ajax({
    type : 'POST',
    url : postUrl,
    data : formData,
    dataType : 'json',
    encode : true
  })
  .done(function(data) {
    if (data.success == true)
    {
      console.log('success');
      console.log(data);

      var redirect = '' + data.token
      $(location).attr('href', redirect);
    }

  });
});

Thanks