Place flour and egg in 2 separate bowls. Combine breadcrumbs, garlic powder and parmesan in a medium bowl. Working in batches, toss zucchini in flour, dip in egg and then coat in crumb mixture. Place half of the crumbed zucchini in air-fryer basket. Spray with oil. Cook for 8 minutes or until golden. Repeat with remaining crumbed zucchini and oil.
To make the zucchini tzatziki, combine all the ingredients in a small bowl. Top with extra mint and season with pepper. Serve with zucchini fries.