MY MACAIR EXPIRE IN 12/2021 CAN I RENEWAL THE APPLE CARE

Hello carmenfrompaterson, This Apple Care + support page may help too on the renewal.

Extend your AppleCare+ coverage - Apple Support

You can only renew AppleCare if you purchased AppleCare at the time you purchased the computer. If you did not do this, you cannot buy coverage when your normal 1 year warranty runs out.

If you already have AppleCare coverage, you have 30 days after it runs out to renew it, not before.