Preheat the air fryer to 400 degrees F (200 degrees C) according to manufacturer's instructions.
Pat tilapia fillets dry using a paper towel. Coat both sides of fish with flour.
Whisk egg, lemon juice, and salt together in a shallow bowl. Place bread crumbs and lemon-pepper seasoning in a separate shallow bowl.
Dip flour-coated fish first in egg and then in bread crumb mixture. Press down on the fish so that the bread crumbs stick. Spray both sides of fish with cooking spray.
Place fillets in the air fryer basket and cook for 5 minutes. Flip fish over using a spatula and cook for 3 minutes more. Serve with lemon wedges.