Carrier billing lets you buy apps, games, or services and pay for them through...

https://milosultimatecolumn.zenbloomer.com/posts/why-does-carrier-billing-show-up-as-a-weird-line-item

Carrier billing lets you buy apps, games, or services and pay for them through your mobile phone account. Instead of using a credit card, the cost is added to your monthly phone bill or taken from your prepaid balance