Payment declined

Hi,

A customer wants to purchase this product. When trying to pay, she gets this message:

“There was an error processing your order. Please check for any charges in your payment method and review your order history before placing an order again.”

Strange, because other customers based in the US were able to purchase. She tried with ApplePay and with her creditcard. I see in WooCommerce at Orders that 1 payment is cancelled and 1 payment is pending. What could be going on?

The page I need help with: [log in to see the link]