Pat the wings very dry with paper towels; damp skin will steam instead of blister.
Toss the wings with the baking powder, salt, 1/2 teaspoon pepper and garlic powder until lightly dusted.
Preheat the air fryer to 390°F for 4 minutes.
Arrange the wings in one layer and air-fry for 12 minutes, then turn every piece.
Cook for 12 to 16 minutes more until the skin is crisp and the meatiest wing reaches at least 165°F.
Whisk the melted butter with the lemon zest, lemon juice and remaining pepper.
Toss the hot wings with the lemon-pepper butter and serve immediately.