1. Combine olive oil, chili flakes, garlic, onion powder, salt, and pepper in a large non-reactive bowl. Mix well. Then, add the chicken fillets. Marinate for at least two hours.
2. Preheat your Air Fryer to 400 F (200 C).
3. Place the marinated chicken fillets in the Air Fryer basket and cook for 15 minutes or until cooked through.