Preheat the air fryer at 390 degrees F for 3 minutes.
Cut bell peppers and onion into even strips, about 2 inches long. Place in a large mixing bowl. Toss with a tablespoon of oil then sprinkle with half the seasoning. Add to the air fryer basket in an even layer.
Slice chicken breasts into even strips, about 2 inches long. Chop garlic then add both to the same bowl the peppers were in. Toss with a tablespoon of oil then sprinkle with remaining seasoning mix. Add the the air fryer basket over the vegetables. Spread the chicken out as much as possible so the edges aren't touching.
Air fry for 10 to 12 minutes, flipping the chicken at the halfway point.
Serve with tortillas and toppings.
Notes
Store leftovers in an airtight container for up to three or four days.
Freeze for up to three months. Use freezer safe containers or ziploc bags.