Finely grate potatoes; firmly squeeze and drain any liquid. Place potatoes in a large bowl. Add egg, onion, flour, salt, pepper and garlic powder; mix well. , Preheat air fryer to 375°. In batches, drop batter by 1/4 cupfuls onto greased tray in air fryer; press lightly to flatten. Spritz with cooking spray. Cook until golden brown, 12-17 minutes. Serve immediately.