Cryptocurrency prices are volatile. When we quote a price in crypto, we can only honor that price for 30 minutes—after which time the exchange rate may have changed. If your order expires, don’t worry! Simply reload the page to generate a new order with an updated 30-minute payment window.
Be mindful that this will generate a new crypto address so be sure to use the new address before sending your payment.
We provide more information about reusing addresses on Bitrefill here.