Carrier billing lets you buy apps, games, or services and have the cost added...

https://www.nav-bookmarks.win/carrier-billing-lets-you-buy-apps-games-or-digital-content-and-have-the-cost

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