Add all ingredients to the inner pot of an Instant Pot (we have a 6qt). If you are using a chicken carcass that is already stuffed with onion, garlic, and herbs, don't add the extras.
Fill the inner pot with water to the "Max Fill" line. Place the lid on the pot and twist to lock, set the knob to the "Seal" position, and press the "Soup" button (or manual on High pressure for 30 minutes).
Once the cycle is complete, you can do wither NPR or QPR (whichever you have the time for). NPR is best but you'll still get a good broth with QPR.
Remove as much of the carcass and veggies with a large slotted spoon and set aside in a bowl (do not discard yet). Place a small wire mesh strainer in a canning funnel and put it on a canning jar (we prefer to use quart and half gallon jars). Pour the broth directly into the jars. Tightly screw on the lids.
Put the carcass and veggies back in the Instant Pot, fill half full with water this time. Repeat the cooking and canning process the same way you did it the first time.
After the second batch of broth, remove any remaining chicken from the carcass and reserve to add to the broth for a heartier soup or to add to casseroles or any other dish you want.
Store broth in the fridge for up to a week. For longer storage, freeze the broth in silicone molds (of your preferred size). Remove from molds once frozen solid and store them in a zip-top bag in the freezer for up to 6 months.