Carrier billing lets you pay for apps, games, or subscriptions by charging the...

https://www.bookmark-xray.win/carrier-billing-lets-you-buy-apps-games-or-services-using-your-phone-instead

Carrier billing lets you pay for apps, games, or subscriptions by charging the amount directly to your phone bill. If you have a monthly plan, the cost appears on your next bill. For pay-as-you-go users, the purchase is deducted from your available credit