Subscriptions and purchases on the PNP website are managed through Paypal as a service provider.
You can see the status of your subscription in your Billing history, and make changes to it in your My account section. Find both of these sections by selecting your name in the top right of the page.
If you made your purchase through your own Paypal account, you can find the instructions for managing your purchases and subscriptions through your Paypal account HERE.