Preheat an air fryer to 400 degrees F (200 degrees C).
Combine flour, salt, and pepper in a bowl.
Pour ranch dressing into a bowl.
Combine bread crumbs, Parmesan cheese, and garlic powder in a third bowl.
Dredge each piece of zucchini in flour mixture and then dip into ranch dressing, coating both sides and shaking off excess dressing. Dip into bread crumb mixture next, pressing the breading lightly onto each zucchini chip.
Spray the air fryer basket with cooking spray, then place breaded zucchini chips in the basket in a single layer. Cook for until browned, 5 to 6 minutes. Repeat with remaining zucchini chips.