Pay-by-phone lets you buy online and charge purchases directly to your monthly...

https://wiki-aero.win/index.php/Face_ID_Checkout_vs_Carrier_Billing:_Which_Is_Faster%3F

Pay-by-phone lets you buy online and charge purchases directly to your monthly phone bill or prepaid credit. It’s a simple, secure way to pay without needing a credit card or separate account. Perfect for quick checkouts on mobile devices.