Carrier billing lets you buy apps, games, or services and have the cost added...
https://www.bookmarkidea.win/carrier-billing-lets-you-buy-apps-games-or-other-digital-content-and-charge
Carrier billing lets you buy apps, games, or services and have the cost added directly to your monthly phone bill or taken from your pay-as-you-go credit. It’s a simple way to pay without needing a credit card or separate account