Scrub your potatoes clean, then use a fork or knife to prick them all over. This will prevent the potatoes from bursting in spots while air frying.
To cook with the optional oil
Use a silicone brush or your hands to spread the oil over the surface of your potatoes and then air fry at 400 degrees F for 20-30 minutes, until soft and a fork easily pierces the potato.
For oil free
Air fry the potatoes at 350 degrees F for 25-35 minutes, until soft and easily pierced with a fork. Using a lower temperature without the oil, prevents the skin from burning before the inside has a chance to cook through.