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

https://www.insert-bookmark.win/carrier-billing-lets-you-buy-digital-goods-or-services-using-your-phone-the

Carrier billing lets you buy apps, games, or services and have the cost added directly to your monthly phone bill or subtracted from your pay-as-you-go credit. It’s a simple way to pay without entering card details or account info