In a bowl, mix soy sauce, honey, oyster sauce, sesame oil, garlic, ginger, black pepper, and red pepper flakes.
Place chicken thighs in the bowl and coat evenly with the marinade. Let sit for 15 minutes.
Preheat the air fryer to 380°F (190°C).
Arrange chicken thighs skin-side down in the air fryer basket. Cook for 12 minutes.
Flip the chicken and cook for another 10–12 minutes until golden brown and crispy.
Optional: Transfer marinade to a saucepan, add cornstarch, and simmer until thickened.
Brush thickened sauce over chicken before serving.
Garnish with chopped green onions and sesame seeds. Serve hot!