Pay-by-phone transactions let you buy digital goods and services quickly using...

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

Pay-by-phone transactions let you buy digital goods and services quickly using your mobile device. Charges are added directly to your monthly phone bill or deducted from your prepaid credit, making checkout simple without needing a credit card