Pay-by-phone transactions let you charge purchases directly to your mobile...
https://uniform-wiki.win/index.php/What_is_Direct_Carrier_Billing_(DCB)_in_Plain_English%3F
Pay-by-phone transactions let you charge purchases directly to your mobile phone bill or use prepaid credit. It’s a simple, mobile-friendly way to pay for apps, games, and digital services without needing a credit card