我想将我的网站与AppStore集成，让客户通过AppStore付款

import StoreKit

class ViewController: UIViewController, SKProductsRequestDelegate, SKPaymentTransactionObserver {
    
    var product: SKProduct?
    
    override func viewDidLoad() {
        super.viewDidLoad()
        SKPaymentQueue.default().add(self)
        fetchProduct()
    }
    
    func fetchProduct() {
        let productID = "com.example.product"
        let request = SKProductsRequest(productIdentifiers: Set([productID]))
        request.delegate = self
        request.start()
    }
    
    func productsRequest(_ request: SKProductsRequest, didReceive response: SKProductsResponse) {
        if let product = response.products.first {
            self.product = product
        }
    }
    
    func buyProduct() {
        guard let product = product else { return }
        let payment = SKPayment(product: product)
        SKPaymentQueue.default().add(payment)
    }
    
    func paymentQueue(_ queue: SKPaymentQueue, updatedTransactions transactions: [SKPaymentTransaction]) {
        for transaction in transactions {
            switch transaction.transactionState {
            case .purchased:
                completeTransaction(transaction)
            case .failed:
                failedTransaction(transaction)
            case .restored:
                restoreTransaction(transaction)
            default:
                break
            }
        }
    }
    
    func completeTransaction(_ transaction: SKPaymentTransaction) {
        // Handle successful purchase
        SKPaymentQueue.default().finishTransaction(transaction)
    }
    
    func failedTransaction(_ transaction: SKPaymentTransaction) {
        if let error = transaction.error as NSError? {
            if error.code != SKError.paymentCancelled.rawValue {
                // Handle error
            }
        }
        SKPaymentQueue.default().finishTransaction(transaction)
    }
    
    func restoreTransaction(_ transaction: SKPaymentTransaction) {
        // Handle restored transaction
        SKPaymentQueue.default().finishTransaction(transaction)
    }
}