Hello!
Jesse from the Guru Team here.
While this would be considered a bit of hack you can achieve this with a bit of JS:
<script> window.location =" http://YOURURLHERE.COM"; </script>
Replace yoururlhere.com with your desired page, and place the code in the additional content and scripts section found in the Checkout section of the admin.
Feel free to reach out at any time if you have any other questions.