Wash and slice the squash into circular 1/2-inch slices. Discard the ends. Dip the slices into the egg and then the flour. Preheat the air fryer according to your brand. The Ninja says 3 minutes. After preheating your air fryer,  place the pieces in the air fryer basket. Lightly coat vegetable spray on the sliced squash. I used a rack inside the air basket so I could cook two layers. Bake at 390 degrees for 15 minutes.