Hi vereato,
You need to turn on the Auto Return in your PayPal Profile and you can specify the return url.
If you have multiple return url's, then you need to specify the return url in your button code in the section Take my customer to this url when they finish checkout.
Following is the steps to enable Auto Return from PayPal website.
- Go to the Account Settings.
- Click Website payments.
- Click Update across from "Website preferences".
- Click on under "Auto Return".
- In the Return URL field, enter the URL where you want to send your buyer after the payment.
- The Return URL is applied to all Auto Return payments unless otherwise specified within the payment button or link.
- Click Save.
Reference:
https://www.paypal.com/us/cshelp/article/how-do-i-use-paypals-auto-return-feature-help197
https://www.paypal-community.com/t5/How-to-use-PayPal-Archive/Redirect-to-new-URL-after-payment/m-p/17779/highlight/true#M36608