Slice the onions. Core and slice bell pepper(s). Pat the chicken breasts dray and cut into strips.
Place onions, bell peppers, chicken and olive oil in a bowl. Add all the seasonings to the bowl, then mix thoroughly until everything is well covered.
Preheat the air fryer to 390°F. Coat the air fryer basket with cooking spray (optional).
Add chicken fajita mix to the the basket. Cook for 12-14 minutes or until fully cooked (mix/toss after 8 minutes). Squeeze half of a lime over the chicken fajitas. Season with salt and pepper to taste.