Edit in JSFiddle

Formio.createForm(document.getElementById('formio'), 'https://examples.form.io/example').then(function(form) {
  // Defaults are provided as follows.
  form.submission = {
    data: {
      firstName: 'Joe',
      lastName: 'Smith'
    }
  };
  
  // Register for the submit event to get the completed submission.
  form.on('submit', function(submission) {
    console.log('Submission was made!', submission);
  });
  
  // Everytime the form changes, this will fire.
  form.on('change', function(changed) {
    console.log('Form was changed', changed);
  });
});

<div id="formio"></div>