In a large bowl, add the chicken thighs along with garlic powder, onion powder, cayenne pepper, salt, black pepper, cumin, and avocado oil. Mix well to evenly coat the chicken.
Cover and marinate for at least 30 minutes.
If using wooden skewers, soak them in water for 20–30 minutes to prevent burning.
Thread the marinated chicken pieces onto skewers.
Preheat the grill to medium-high heat. Grill the skewers, turning occasionally, until the chicken is fully cooked and reaches an internal temperature of 165°F.
Brush the chicken with barbecue sauce during the last few minutes of grilling.
Remove from the grill and serve warm.