As there has been a lot of question raised about this issue, this article purpose is to give you a closer look at how to make Paypal auto redirect.
Login to https://www.sandbox.paypal.com/ by a business PayPal sandbox account.
Check auto run “On” and set the URL AUTO REDIRECT into the “Return URL” like this image.
Then save it.
3. Finally, use this PayPal sandbox account and set for the PayPal email in Engine Settings => Settings => Payment => Paypal email.
You must use a business PayPal account to set the return URL. Paypal doesn’t allow to set the return URL if you use a personal PayPal account.