Preheat the air-fryer to 400 F. In a shallow dish, whisk together egg and milk. Combine breadcrumbs and grated parmesan cheese in another dish.
Fully coat each chicken tender into the egg mixture, then fully coat in the breadcrumbs. Place into a greased air-fryer basket. Air-fry for 12-15 minutes. Top with marinara sauce, and cheese, and air-fry for another 3-5 minutes.