Pay-by-phone lets you buy digital goods and services with just your mobile...

https://page-wiki.win/index.php/Carrier_Billing_vs_Apple_Pay:_Which_Is_Easier_on_a_Phone%3F

Pay-by-phone lets you buy digital goods and services with just your mobile device. Charges go straight to your monthly phone bill or use prepaid credit if you have it. It’s a simple way to pay without needing a credit card or bank details during checkout.