If you integrate PayPal payment gateway in your website or application when a user pay he does not return back to prev page automatically. You will be need of auto return after payment. PayPal auto return is turned off by default. You have to enable it in your PayPal business account.

Here are the following steps to enable this:

PayPal Auto Return

1. Login to PayPal business account using your account login details.
2. Click on Profile or Setting icon in Nav menu on right side.
3. A drop-down will open, now click on Profile and Settings. 
4. You will be redirected to My Profile page. Now click on Selling tools on your left side.
5. You will see in you right side setting options. Click on the update in front of Website preferences on the right side.
6. You will be redirected to Website Payment Preferences page. Now in Auto Return for Website Payments click on On radio button and provide Return URL.
7. Save the setting.

Now you have successfully enabled Auto Return. A user will be returned back automatically after payment.