Trying to extend AppleCare but keeps saying device is already covered, how do we get past this or what options are we to pick to extend the AppleCare?

There is information in Extend your AppleCare+ coverage - Apple Support including the following:

To continue your coverage, visit mysupport.apple.com. In the United States, Canada, and Australia, you can continue your coverage within 60 days of the end date of your original coverage. In Japan, you can continue your coverage within 30 days of the end date of your original coverage.