[Link to subscription and app settings] #ios

uiapplication.swift

extension UIApplication {
    class func openAppSettings() {
        guard let url = URL(string: self.openSettingsURLString) else { return }
        self.shared.open(url, options: [:], completionHandler: nil)
    }
    
    class func openSubscriptionManagement() {
        guard let url = URL(string: "itms://apps.apple.com/account/subscriptions") else { return }
        self.shared.open(url, options: [:], completionHandler: nil)
    }
}