How do I integrate PayPal Checkout Recurring Payments in Magento?
To determine the version of Magento you have, log in to your Magento admin panel and scroll to the bottom of the page. The footer will display your version.
For complete information on integrating PayPal Checkout Recurring Payments with your Magento shopping cart, see their instructions on Recurring Profiles.
Note: Check that you have PayPal Billing Agreements enabled for Recurring Payments to work correctly. For details, see Magento's complete steps on Billing Agreements.
Magento Documentation and Resources