Carrier billing lets you pay for apps, games, or digital content by adding the...

https://bizzmarkblog.com/carrier-billing-for-subscriptions-is-it-easy-to-cancel/

Carrier billing lets you pay for apps, games, or digital content by adding the cost to your monthly phone bill or deducting it from your prepaid credit. It’s a simple way to buy without needing a credit card or separate payment app