Why can’t I find the ‘Miles Plus Cash’ option on HK Express’ payment page?

You may have selected a foreign currency or voucher for your booking, which are not eligible for ‘Miles Plus Cash’ bookings. In this case, please ensure that the default currency is selected and no voucher is applied.

More about redeeming HK Express flights

How do I pay for HK Express flights with my Asia Miles?
How many miles are required for HK Express flights?
Can I use Asia Miles to pay for HK Express promo fares?
Can I use Asia Miles to book a flight ticket for anyone other than myself?
Can I use Asia Miles to book a HK Express flight ticket for an infant or a child?
Can I use Asia Miles to pay for HK Express extras?
Can I choose a mix of Miles and cash to redeem my flight?
Can I use Asia Miles to settle any tax and surcharge?
Can I rebook or refund my booking?
Can I earn Asia Miles for HK Express flight bookings?
I cannot successfully book a flight with Asia Miles on HK Express website. Who should I contact?