Stir together flour, smoked paprika, and 1/4 teaspoon of the salt in a shallow dish.
In another shallow dish lightly beat egg and water.
Stir together panko and remaining 1/4 teaspoon salt in a third shallow dish.
Dredge onion rings in flour mixture, shaking off excess. Then dip in egg mixture, allowing any excess to drip off. Finally dredge the onion rings in the panko mixture, pressing the sides so that it sticks. T
Coat both sides of the onion rings with cooking spray.
Place each onion rings in the air fryer basket in a single layer. Cook at 375°F for approximately 10 minutes or until golden brown and crispy on both sides, flipping onion rings at the 6-minute mark. Cover to keep warm while cooking remaining onion rings.