final class IAPManager: NSObject, SKProductsRequestDelegate, SKPaymentTransactionObserver {
    static let shared = IAPManager()

    private var products = [SKProduct]()
    private var completion: (() -&gt; Void)?
    private var productBeingPurchased: SKProduct?

    enum Product: String, CaseIterable {
        case removeAds = &#34;JokesRUs.RemoveAds1&#34;
        case summerIcon = &#34;JokesRUs.Icons.Summer&#34;
        case tacoIcon = &#34;JokesRUs.Icons.Taco&#34;
        case pizzaIcon = &#34;JokesRUs.Icons.Pizza&#34;
        case hotdogIcon = &#34;JokesRUs.Icons.HotDog&#34;
        case hamburgerIcon = &#34;JokesRUs.Icons.Hamburger&#34;
        case doughnutIcon = &#34;JokesRUs.Icons.Doughnut&#34;
        case support1 = &#34;JokesRUs.Support.One&#34;
        case support5 = &#34;JokesRUs.Support.Five&#34;
        case support10 = &#34;JokesRUs.Support.Ten&#34;
        case support20 = &#34;JokesRUs.Support.Twenty&#34;
    }
    let group = DispatchGroup()
    
    public func fetchProducts() {
        let request = SKProductsRequest(productIdentifiers: Set(Product.allCases.compactMap(({ $0.rawValue }))))
        request.delegate = self
        request.start()
    }
    func productsRequest(_ request: SKProductsRequest, didReceive response: SKProductsResponse) {
        print(&#34;products returned = \(response.products.count )&#34;)
        products = response.products
    }
    func request(_ request: SKRequest, didFailWithError error: Error) {
        guard request is SKProductsRequest else {
            return
        }

        print(&#34;Product fetch request failed&#34;)
    }
    public func purchase(product: Product, completion: @escaping (() -&gt; Void)) {
        print(&#34;product = \(product)&#34;)
        print(&#34;can make payments = \(SKPaymentQueue.canMakePayments())&#34;)
        guard SKPaymentQueue.canMakePayments() else {
            return
        }
        print(&#34;product = \(product.rawValue)&#34;)
        guard let storeKitProduct = products.first(where: { $0.productIdentifier == product.rawValue }) else {
            return
        }
        Utilities.purchaseFailed = false
        print(&#34;call purchase&#34;)
        let paymentRequest = SKPayment(product: storeKitProduct)
        SKPaymentQueue.default().add(self)
        SKPaymentQueue.default().add(paymentRequest)
        print(&#34;Payments pending = \(SKPaymentQueue.default().transactions)&#34;)
        completion()
//        self.completion = completion
    }