Pat the chicken thighs dry with paper towels to ensure crispy skin.
In a small bowl, mix together kosher salt, black pepper, and smoked paprika.
Rub the seasoning mixture evenly over both sides of each chicken thigh.
Preheat the air fryer to 380°F (193°C) for 5 minutes.
Place the chicken thighs skin-side down in the air fryer basket in a single layer.
Cook for 9 minutes, then flip the chicken thighs skin-side up and cook for an additional 9 minutes or until the internal temperature reaches 165°F (74°C) and the skin is crispy.
While the chicken cooks, melt the butter in a small saucepan over medium heat.
Add the minced garlic to the melted butter and cook for 1-2 minutes until fragrant, stirring frequently to avoid burning.
Remove the garlic butter from heat and stir in the chopped parsley.
Once the chicken is done, transfer it to a serving plate and brush generously with the garlic butter sauce.
Serve immediately and enjoy your crispy, flavorful air fryer garlic butter chicken thighs.