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

https://rileysexcellentnews.readspirex.com/posts/is-pay-by-phone-billing-the-same-as-a-mobile-wallet

Carrier billing lets you buy apps, games, or subscriptions and have the cost added to your monthly phone bill or taken from your prepaid credit. It’s a simple way to pay without entering card details, making small purchases easier on your phone.