Pop up on Exiting Page

Hi

I'm trying to configure the Hustle pop up/slide to show when a user leaves a page but can't seem to get it working.

Basically, the site is a directory, and I want it to show a specific offer or call to action to each listing (or each listing that wants one) so when the user intends to leaves listing A, it'll show a pop up/slide in but if they were to intend leaving listing B, it shows a different one.

I added the 'only on specific urls' but it didn't work for me.

Thanks
Farzan