Preheat the air fryer to 400℉.
Now, take the Brussels sprouts straight from the freezer and pour into the air fryer. Do not stack them, allow room for them to roll a little. Do not add seasoning because it'll just fall off as they thaw while cooking.
Quick tip, if you allow them to thaw or if you're using fresh, you can toss the sprouts in vegetable oil to give them a crispy texture at the end.
Air fry the Brussels sprouts for 10 minutes. Shake the basket in between the time at the 5 minutes mark.
When the Brussels sprouts are finish you can season and flavor them.