Preheat the air fryer to 400°F (200°C) for 5 minutes.
Using a fork, poke each potato 6-8 times all over to allow steam to escape during cooking.
Rub each potato evenly with olive oil, ensuring the entire surface is coated.
Sprinkle kosher salt evenly over the potatoes, rubbing it into the skin.
Place the potatoes in the air fryer basket, making sure they do not touch.
Cook at 400°F (200°C) for 35-40 minutes, flipping the potatoes halfway through the cooking time to ensure even crisping.
Check doneness by inserting a fork or skewer into the center; it should slide in easily when fully cooked.
Remove the potatoes from the air fryer and let them rest for 5 minutes before serving.