Preheat your air fryer to 380°F (190°C) for about 3-5 minutes.
In a small bowl, mix together smoked paprika, salt, black pepper, chopped onion, minced garlic, and avocado oil to create a marinade.
Place the chicken breasts in a shallow dish or resealable plastic bag and coat them evenly with the marinade. Let them marinate for at least 15-20 minutes to absorb the flavors.
After marinating, remove the chicken breasts from the marinade and place them in the air fryer basket in a single layer (rounded side down).
Cook chicken breasts in the air fryer at 380°F (190°C) for 22 minutes until they are golden brown on the outside and reach an internal temperature of 165°F (74°C). Flip them halfway through the cooking time for even cooking.
Once cooked, remove the chicken breasts from the air fryer and let them rest for a few minutes before slicing or serving.
Garnish with fresh herbs or lemon wedges if desired, and serve with your favorite side dishes.