In a shallow bowl, stir together flour, paprika, and 1/4 teaspoon of the salt.
In a second shallow bowl, lightly beat egg and water.
In a third shallow bowl, stir together breadcrumbs and 1/4 teaspoon salt.
Dredge onion rings in flour mixture, shaking off excess. Dip in egg mixture, allowing any excess to drip off. Dredge in breadcrumbs mixture, pressing to adhere. Coat evenly.
Lightly spray air fryer basket with oil.
Place the rings in a single layer in the air fryer basket. Make sure there is space between them. Cook in batches if required.
Cook at 375°F until golden brown and crispy, about 10-12 minutes.
Once cooked, lift out the onion rings with a fork and serve.