Adobe Sign WebForm Redirect URI with parameter

For example i have a web form created, using link , i can send parameter this way

https://na2.documents.adobe.com/public/esignWidget?wid=THISWIDGETID*#name=&id=&contact=&pid=PIDVALUE&contract=&sum=

How do i add a parameter such that upon signing complete, do a redirect or server notification to one of my page with PIDVALUE send over. so i can capture that the form is "signed" by PIDVALUE by capturing HTTP GET of argument pid

Thank you