Meanwhile, remove salmon from the freezer and any packaging.
Whisk together the remaining ingredients in a small bowl and set aside.
Place salmon, skin side down on the trays or in the basket of an air fryer. Air fry at 400°F for 7 minutes.
Open the air fryer and brush the maple mustard sauce onto the tops of each filet of salmon reserving any extra sauce.
Air fry for another 5 minutes until salmon is cooked through. For extra thick filets, you may need 6-7 minutes. For thinner filets, 3-5 minutes. (*See note)
Remove salmon from the air fryer and serve with any remaining sauce.
Notes
*Salmon is cooked through at a temperature of 145 degrees F. Use an instant read thermometer for best results.