Wash and trim the green beans, snapping off the stem ends. Pat them very dry with paper towels since any moisture will prevent the breading from sticking properly.
Set up a three-part breading station. Place the flour in the first shallow dish. Beat the eggs in the second dish. In the third dish, combine the panko breadcrumbs, parmesan cheese, garlic powder, onion powder, smoked paprika, salt, and black pepper, tossing to mix.
Working with a small handful at a time, dredge the green beans in the flour and shake off excess. Dip them into the beaten egg, letting any excess drip off, then press them into the panko mixture, turning and pressing to coat all sides.
Preheat the air fryer to 400 degrees F. Arrange the breaded green beans in a single layer in the basket without stacking them. Spray the tops generously with cooking spray. You will likely need to cook in 2 batches.
Air fry for 8 to 10 minutes, shaking the basket gently halfway through, until the green bean fries are golden and crispy on the outside while still having a slight snap when you bite through.
Serve the green bean fries hot with ranch dressing or your favorite dipping sauce on the side.