Accept in-app payments

class MyCheckoutVC: UIViewController {
 func loadCheckout() {
    let intentConfig = PaymentSheet.IntentConfiguration(
      mode: .payment(amount: 1099, currency: "USD")
    ) { [weak self] _, _, intentCreationCallback in
      self?.handleConfirm(intentCreationCallback)
    }
    var configuration = PaymentSheet.Configuration()
    configuration.returnURL = "your-app://stripe-redirect" // Use the return url you set up in the previous step
    PaymentSheet.FlowController.create(
      intentConfiguration: intentConfig,
      configuration: configuration
    ) { [weak self] result in
      switch result {
        case .failure(let error):
          print(error)
        case .success(let paymentSheetFlowController):
          self?.paymentSheetFlowController = paymentSheetFlowController
          // Update your UI paymentSheetFlowController.paymentOption.image and paymentSheetFlowController.paymentOption.label
      }
    }
  }

  func handleConfirm(_ intentCreationCallback: @escaping (Result<String, Error>) -> Void) {
    // ...explained later
  }
}

paymentSheetFlowController.presentPaymentOptions(from: self) {
  // Update your UI using paymentSheetFlowController.paymentOption
}

// Create an updated IntentConfiguration
var updatedIntentConfig = oldIntentConfig
updatedIntentConfig.amount = 999
// Disable your "Buy" and "Payment method" buttons and call `update`
paymentSheetFlowController.update(intentConfiguration: updatedIntentConfig) { [weak self] error in
  if error != nil {
    // You must retry - until the update succeeds, the customer can't pay or select a payment method.
    // For example, you can automatically retry the update with an exponential back-off, or present the user with an alert that retries the update.
  } else {
    // Re-enable your "Buy" and "Payment method" buttons
    // Update your UI using paymentSheetFlowController.paymentOption.image and paymentSheetFlowController.paymentOption.label
  }
}

class MyCheckoutVC: UIViewController {
  // ...
  func didTapBuyButton() {
    paymentSheetFlowController.confirm(from: self) { paymentResult in
      switch paymentResult {
      case .completed:
        // Payment completed - show a confirmation screen.
      case .failed(let error):
        // PaymentSheet encountered an unrecoverable error. You can display the error to the user, log it, etc.
        print(error)
      case .canceled:
        // Customer canceled - you should probably do nothing.
      }
    }
  }

  func handleConfirm(_ intentCreationCallback: @escaping (Result<String, Error>) -> Void) {
    // Make a request to your own server.
    let myServerResponse: Result<String, Error> = ...
    switch myServerResponse {
    case .success(let clientSecret):
      // Call the `intentCreationCallback` with the client secret
      intentCreationCallback(.success(clientSecret))
    case .failure(let error):
      // Call the `intentCreationCallback` with the error
      intentCreationCallback(.failure(error))
    }
  }
}