For Version 9.00, 8.00 and 7.00
For these VPCart versions, the Paypal is already built-in for IPN by default.
So basically you do no need to enable IPN and set the notification URL through PayPal.
The VPCart itself will send these parameters to PayPal automatically and PayPal will send back the approval information based on the parameters.
However, if you found the notification does NOT update on your orders, you can refer to the below helpnote to set up correct Notification URL (IPN) :
https://helpnotes.vpcart.com/kb/23-Payments/1260-PayPal-Instant-Payment-Notifications-IPN-Warning-Email/
For Version 6.50 And Below
Please follow these steps below to set up Auto Return in Paypal site if you are using V650 and below versions :
1) Log in to your PayPal business account at www.paypal.com.
2) Mouse over to your profile menu on the top right, click Account Settings.
3) In the left panel, click Website payments.
4) Locate the "Instant payment notifications" section and click Update.
5) Click Choose IPN Settings to specify your listener's URL and activate the listener.
6. Specify the new URL for your listener in the Notification URL field :
http(s)://www.example.com/paypalipnresult.asp (if using Paypal IPN)
or http(s)://www.yoursite.com/paypalresult.asp (if not using IPN).
Note: If you have already follow above and still not receiving any IPN response from Paypal, you may refer to the below helpnote from Paypal:
https://www.paypal.com/us/selfhelp/article/why-didn't-i-receive-any-ipn-posts-ts1006
You can also follow the official Paypal guide on how to set the auto return in this link below :
https://www.paypal.com/us/cgi-bin/webscr?cmd=p/mer/express_return_summary-outside