Again despite what all the hype you’ve seen for Air Fryers, to cook fries in particular, and any coated fried food, you’re going to need some oil. Frozen Fries often come with enough on them, straight from the freezer. Fresh chips/fries will definitely need a little oil sprayed on.
Without oil, you will end up with poorly cooked fries, possibly burnt at the edges. With oil it will crisp up the outside and cook through making a nice fluffy inside…. perfect. Ensure you turn or shake the contents at least once during the cooking cycle to give a better coverage.
Avoid the aerosol type oil dispenser, the propellant is NOT good for your health, long term, buy a pump bottle and use it with your favourite cooking oil.