PayPal integration for reoccuring payment

I am a developer and I'm after some C# code for .NET Core. I've not done Paypal / online payments before. Whilst I'm usually fine with consuming APIs, because this is around payment, I would rather have help then go by myself and get into potential trouble. On my website, a user needs to be able to subscribe to one or more services, which will be billed periodically via the Paypal gateway. When they complete payment, my website needs to call certain logic to enable the servie(s). When the user cancels their subscription, from my website or from their Paypal account, my website needs to be notified so it can perform the neccessary logic. If a user cancels within 5 days of making a payment (regardless of it being the first of not), the user will be automatically refunded that single payment. I will not store any financial records. Paypal can deal with that! Autofac favoured but not vital. The code doesn't have to be well documented and I expect to be able to have a quick walk through at the end to ensure I've understood what you've written and why. I also expect to see an example website where you have implemented recurring payments.