how many more payments

You need to ask the bank your arranged the payments with. If you charged to an Apple Card open the Wallet, tap on the Apple Card, then the 3 dots in a circle at the top left, and View Installments. If you are paying through your carrier, log on to the carrier’s customer portal.

Hi,

You'd have to check with provider of the split payment (financing) service.

If you purchased it with an Apple Card, you should be able to view the invoice in the Wallet app on your iPhone (How to view and pay Apple Card Monthly Installments - Apple Support).

If you purchased it via a cellphone carrier, I'd suggest you reach out to them and they should be able to provide that information.