Preheat the air fryer to 400°F (200°C).
In a large mixing bowl, combine the chicken cubes with olive oil, sumac, garlic powder, onion powder, salt, pepper, and lemon juice.
Toss the mixture until every piece of chicken is thoroughly and evenly coated with the seasoning.
Arrange the chicken in a single, non-overlapping layer in the air fryer basket to ensure maximum airflow and even cooking.
Cook for 12 to 15 minutes, shaking the basket at the 7-minute mark to rotate the pieces.
Verify that the internal temperature of the chicken has reached 165°F (74°C) using a digital meat thermometer.
Remove from the air fryer and allow to rest for 2 minutes before serving.