Heat a 5 1/2-quart or larger air fryer to 350 to 360°F. Meanwhile, place 6 tortillas in a single layer on a cutting board. Spray each tortilla lightly with cooking spray. Sprinkle with 1/4 teaspoon of the kosher salt. Flip the tortillas and repeat spraying and salting the other side. Stack the tortillas and cut into 6 wedges.
Arrange half of the tortilla wedges in an even layer in the air fryer basket; some overlap is OK. Air-fry until lightly browned and crisp, shaking the basket or using tongs to redistribute into an even layer halfway through cooking, 5 to 6 minutes total. Transfer to a wire rack to cool and crisp. Repeat air frying the remaining tortilla wedges, checking for doneness a minute or two earlier.