How can I trigger my form to pop up once a customer is about to leave the website?

Hello,

I'd like to know how I can edit the criteria that makes my response form pop-up? I would like it to pop up once a customer is about to leave the website. 

I'm sorry, but we do not have this type of embed option in the form builder. You may consider installing a script on your website that does this function. It is called the Exit Intent Popup. Here are scripts you can check:

http://beeker.io/exit-intent-popup-script-tutorial

https://codepen.io/ashwin9/pen/eJQOeg