Save payment details after payment

curl https://api.stripe.com/v1/customers \
  -u "
sk_test_BQokikJOvBiI2HlWgH4olfQ2
:" \
  -d name="Jenny Rosen" \
  --data-urlencode email="jennyrosen@example.com"

curl https://api.stripe.com/v1/payment_intents \
  -u 
sk_test_BQokikJOvBiI2HlWgH4olfQ2
: \
  -d "setup_future_usage"="off_session" \
  -d "customer"="{{CUSTOMER_ID}}" \
  -d "amount"=1000 \
  -d "currency"="usd" \
  -d "payment_method_types[]"="card_present"

import UIKit
import StripeTerminal

class PaymentViewController: UIViewController, ReaderDisplayDelegate {
    // Label for displaying messages from the card reader
    let readerMessageLabel = UILabel(frame: .zero)
    var collectCancelable: Cancelable? = nil

    // ...

    // Action for a "Subscribe" button
    func subscribeAction() throws {
        let params = try PaymentIntentParametersBuilder().setCustomer(
"{{CUSTOMER_ID}}").build()
        Terminal.shared.createPaymentIntent(params) { createResult, createError in
            if let error = createError {
                print("createPaymentIntent failed: \(error)")
            } else if let paymentIntent = createResult {
                print("createPaymentIntent succeeded")
                let config = try CollectConfigBuilder().setAllowRedisplay(AllowRedisplay.always).build()
                self.collectCancelable = Terminal.shared.collectPaymentMethod(paymentIntent, config) { collectResult, collectError in
                    if let error = collectError {
                        print("collectPaymentMethod failed: \(error)")
                    } else if let collectPaymentMethodPaymentIntent = collectResult {
                        print("collectPaymentMethod succeeded")
                        // ... Confirm the PaymentIntent
                        Terminal.shared.confirmPaymentIntent(collectPaymentMethodPaymentIntent) { confirmResult, confirmError in
                            if let error = confirmError {
                                print("confirmPaymentIntent failed: \(error)")
                            } else if let confirmedPaymentIntent = confirmResult {
                                print("confirmPaymentIntent succeeded")
                            }
                        }
                    }
                }
            }
        }
    }