How to configure PayPal on my form?

My clients are getting an error message when they click pay with paypal ( or anything for that matter) I can't find where the location is to check what account is listed?

I have jut tested the form integrated with PayPal on your form and I got the following error: 

To resolve it you need to simply enter your PayPal email address where you need the payments sent to, that can be done on the form builder, here is how: 

I hope this helps.