Rub the chicken down with salt and pepper, squeeze half a lemon over top. Separate the skin from the meat on top of the breast and stuff 3 of the 4 sliced cloves under the skin.
Rub the jarred pesto overtop of the chicken skin, underneath with the garlic, and in the cavity. Stuff 1/4 of the onion and half the lemon into the cavity of the chicken (you may have to slice it to make it fit).
Add the trivet to the Ninja Foodi and place the chicken on top. Surround the chicken with the rest of the onion. Add the liquid. Place the lid on top of the Foodi and seal. Turn on high pressure for 22 minutes. Let the pressure come down naturally for 5 minutes. Then release the vent.
Remove the lid and close the air fryer lid. Air fry for 12-15 minutes at 400F. Let the chicken rest for 10-15 minutes to let the juices settle.