Step 1: paste this code into all page and checkout page headers

<script src="https://cdn.jasongo.net/ecf.js"></script> 

Thanks, JasonGo. 

Step 2: paste this code into a custom code block where you would like the form to appear. Make sure to replace the URL with your form's URL

<script> 
ECF("https://www.yourdomain.com/offers/abcdefgh/checkout"); 
</script>