How to open the subscriptions page of the App Store app programmatically?

I really think that this is impossible, because when you add a payment to your SKPaymentQueue, and the alertView shows up, your app is no longer active – app store manages eveything outside your app, because later applicationWillResignActive callback is called.

That means, that it was inActive, and the thing you want to do can't be accessed inside your app.

The subscription docs suggest that you can open the subscriptions management page using the following URL

https://developer.apple.com/library/archive/documentation/NetworkingInternet/Conceptual/StoreKitGuide/Chapters/Subscriptions.html#//apple_ref/doc/uid/TP40008267-CH7-SW8

So something like

        let subscriptionURL = URL.init(string: "https://buy.itunes.apple.com/WebObjects/MZFinance.woa/wa/manageSubscriptions")!
        UIApplication.shared.open(subscriptionURL)

this does work; though it's somewhat indirect. The link opens in Safari which then redirects through to the store link. The redirect is actually to

itmss://buy.itunes.apple.com/WebObjects/MZFinance.woa/wa/manageSubscriptions

so I'm using that directly in my app - though of course it isn't guaranteed to be stable.

NB: Sandbox Subscriptions will not appear in this page. You'll have to do a trial signup to some other live service to have anything to see when you test.