Preheat air fryer to 400°. Sprinkle steak with salt and pepper. Place steak on tray in air-fryer basket. Cook until meat reaches desired doneness (for medium-rare, a thermometer should read 135°; medium, 140°; medium-well, 145°), 8-10 minutes, turning halfway through cooking.
Meanwhile, combine butter, parsley, garlic and soy sauce. Serve with steak.