Accept Payments with paypal

Hello Sir,

i see the sticky topic for create a paypal app to accept payments and i see this document: http://support.skywarriorthemes.com/wp-content/uploads/2016/07/PayPal-submission.pdf

But how i can reach the page of the document? i dont find any valid link.

For the moment, if i try to fund a project in my site with paypal i obtain the attached screenshot.

I attach another another screen of my settings… maybe i have to do something?

Please help me, thanks and regards