应用程序购买中的IOS不可用产品

import StoreKit

class PurchaseManager: NSObject, SKProductsRequestDelegate, SKPaymentTransactionObserver {
    
    var productsRequest: SKProductsRequest?
    var products = [SKProduct]()
    
    func fetchProducts() {
        let productIdentifiers: Set<String> = ["com.example.virtualcurrency"]
        productsRequest = SKProductsRequest(productIdentifiers: productIdentifiers)
        productsRequest?.delegate = self
        productsRequest?.start()
    }
    
    func productsRequest(_ request: SKProductsRequest, didReceive response: SKProductsResponse) {
        products = response.products
        if products.isEmpty {
            print("No products found")
        } else {
            for product in products {
                print("Product: \(product.localizedTitle) - Price: \(product.price)")
            }
        }
    }
    
    func purchaseProduct(product: SKProduct) {
        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: transaction)
            case .failed:
                failedTransaction(transaction: transaction)
            case .restored:
                restoreTransaction(transaction: transaction)
            default:
                break
            }
        }
    }
    
    func completeTransaction(transaction: SKPaymentTransaction) {
        print("Transaction completed")
        SKPaymentQueue.default().finishTransaction(transaction)
    }
    
    func failedTransaction(transaction: SKPaymentTransaction) {
        if let error = transaction.error as NSError? {
            if error.code != SKError.paymentCancelled.rawValue {
                print("Transaction failed: \(error.localizedDescription)")
            }
        }
        SKPaymentQueue.default().finishTransaction(transaction)
    }
    
    func restoreTransaction(transaction: SKPaymentTransaction) {
        print("Transaction restored")
        SKPaymentQueue.default().finishTransaction(transaction)
    }
}