Configuring PayPal for third-party order fulfillment
Login to your PayPal account, click the Profile navigation link.
Click the My Selling Tools link.
Under the Selling online sub-heading, click the Update link next to API Access.
Click Grant API Permission under Option 1.
Type the following into the Third Party Permission Username input field: karl_api1.getdropstream.com, click the Lookup button.
Under the Available Permissions heading, check the box next to Search your transactions for items that match specific criteria and display the results and Obtain information about a single transaction.