At the moment when I sell my PDF, there is nothing stopping the person copying the link and sharing it.
The way to get around that is to set the document so that only those with approved email addresses can access that document.
So I need Zap to take the email used to pay in PayPal (already part of the Zap) and add give that email address access rights to that specific document.
Access to that document is provided to them via a link set by Active Campaign (already part of the Zap).
So just the middle bit to sort.