Pay-by-phone lets you buy digital goods and services using your mobile device....

https://legacystance.com/frictionless-payments-the-rise-of-pay-by-phone-transactions-in-digital-commerce/

Pay-by-phone lets you buy digital goods and services using your mobile device. Instead of entering card details, charges go directly to your monthly phone bill or prepaid credit. It’s a simple way to pay without sharing sensitive info