Mix softened butter with salt, garlic powder, dried herbs, and black pepper in a small bowl.
Pat chicken breasts dry with paper towels.
Using a sharp knife, cut three diagonal slits on the top of each chicken breast, about ¼-inch deep.
Spread the compound butter generously over the chicken breasts, pushing some into the slits.
Preheat air fryer to 380°F (193°C) for 3 minutes.
Place chicken breasts in the air fryer basket, butter side up, ensuring they don't overlap.
Cook for 10 minutes, then flip and cook for an additional 5-7 minutes until internal temperature reaches 165°F (74°C).
Remove and allow to rest for 3-5 minutes before serving.