Using a sharp knife, slice one area on the drumstick from top to bottom all the way down to the bone. Pull apart the two sides of the slice and begin separating the meat from the bone so that the chicken drumstick is open and flat. Make sure to leave some part of the meat, on the opposite side of the first cut, still connected.
Generously brush sauce over each drumstick. Cover and place in refrigerator to marinate for at least 1 hour.
Place marinated drumsticks in air fryer basket. Cook at 400 F for 25 mins flipping halfway through cooking time. The internal temperature should be at least 165 F.