Apple Pay guidelines clarification

Hello there,

I have a couple of question about Apple Pay guidelines:

• if we offer Apple Pay payment method in our app, can we disable the selection (I mean the method selection NOT the Payment button!) IF certain condition happens? E.g. the user cannot select apple pay payment method because our basket is not ready yet.

• Are we forced to move the apple pay payment method on the top of our selection? E.g. Cards, Cash On Delivery, Coupon, Apple Pay --> Apple Pay, Cards, Cash On Delivery, Coupon

One last technical question:

• when we start the payment process we are gonna create the request and present the sheet BUT we have to call our backend for pre-authorization, is it allowed?

    @objc private func applePayButtonTapped(sender: UIButton) {
        // TODO: Is it allowed?
        // We need to ask to our backend a pre-authorization and THEN procced with Apple Pay flow
        // but this could be done ONLY after the user TAP on BUY with APPLE PAY and BEFORE
        // paymentAuthorizationViewController is called.
        // Are we compliant to do that?
        
        if PKPaymentAuthorizationViewController.canMakePayments(usingNetworks: FakeData.paymentInfo()) {
            let request = PKPaymentRequest()
            request.blablabla = blabla

            let authorizationViewController = PKPaymentAuthorizationViewController(paymentRequest: request)

            if let viewController = authorizationViewController {
                viewController.delegate = self
                present(viewController, animated: true, completion: nil)
            }
        }
    }

Thanks in advance :)