As part of the iPhone upgrade program, what happens to the Apple Care plan on the iPhone you're trading in? Does the full cost of the care plan still need to be paid in full?

I paid 12 installments on the iPhone 12 with AppleCare+ coverage and upgraded to iPhone 13 through Apple Card's upgrade feature and trade-in program. I understand I would still need to pay off the loan on the iPhone 12, but should I be paying the loan off on the device only and not the AppleCare+ coverage on the iPhone 12 since I traded in the device? If I pay off the loan in full (phone + AppleCare), would I get a prorated credit for the care plan?