Select either one of these two options and enter the appropriate data for that selection. The content in the below fields will change according to your selection.
Sandbox is used for testing only.
To test your configuration of PayPal leave the Sandbox radio button selected and save your changes. Then go to the Online Options page and enable the PayPal option. Restart your web service, log on and make a reservation and pay using your buyer Sandbox account. Once you have completed your testing you need to select Live.
This is normally "https://api.sandbox.paypal.com" for the Sandbox and "https://api.paypal.com" for Live. You should not change them unless specific paypal.com urls are provided for your specific region which is not currently the case.
Note: These URLs are not the same as those referred to at Return URL.