Preheat the air fryer to 400°F (200°C).
In a mixing bowl, combine the olive oil, chili powder, cumin, garlic powder, paprika, salt, and black pepper. Mix well to form a marinade.
Cut the chicken breasts into thin strips and add them to the bowl with the marinade. Toss until the chicken is well coated.
Add the sliced bell peppers and onions to the bowl, and toss to combine.
Transfer the chicken and vegetable mixture to the air fryer basket. Spread them out in an even layer.
Cook for 10 minutes at 400°F (200°C). After 5 minutes, shake the basket to ensure even cooking.
Once the cooking time is up, check that the chicken is fully cooked (internal temperature should reach 165°F/74°C). If necessary, cook for an additional 2-3 minutes.
Serve the chicken and veggies in warm tortillas, and enjoy!
Feel free to add your favorite toppings, such as avocado, sour cream, or salsa, to enhance the flavor.