See the information about clients in Getting Started with CyberSource Advanced for the Simple Order API.For general information about the API versions, see Getting Started with CyberSource Advanced for the Simple Order API. The following table shows which Simple Order API version to use for the PayPal Express Checkout features.
Step 1 Log in to https://developer.paypal.com using your master Sandbox developer account.To make testing easier, check the Log me in automatically box. This option makes it quicker for you to approve the test payments you process through the CyberSource and PayPal test environments.
Step 2 Click Accounts in the left pane to view your Sandbox Business and Buyer accounts.
Step 3
Step 4 Navigate to https://www.sandbox.paypal.com/signin/ in a new browser tab.
Step 6
Step 7 Click My selling tools in the left pane.
Step 8
Step 9
Step 10
Step 11 For testing, enter cybersource_paypal_api1.cybersource.com, which is the CyberSource API account username.For live transactions, enter paypal_cybersource_api1.cybersource.com.
Step 12 Click Lookup.
Step 13
Step 14 Click Add.
Step 15 To edit or view permissions, click the Edit Third Party button on the Manage Third Party Access page.