Preheat the air fryer to 390°F for 3 minutes. Do not thaw the wedges.
In a small bowl, stir together the kosher salt and garlic powder; set aside.
Add the frozen potato wedges to the basket or rack in a single layer with a little space between pieces. Lightly mist with oil spray.
Air fry for 8 minutes.
Turn the wedges with tongs (rotate trays if your fryer has more than one level), spritz again, and cook 7–8 minutes more until the edges are crisp and the centers are tender.
Transfer wedges to a bowl, sprinkle with the salt–garlic mixture, toss well, and return to the air fryer for 1 minute to set the seasoning.
Let rest 1 minute for the crust to firm up, then serve immediately.