Peel the onion and slice it into rounds about 1/2 inch thick. Separate the rounds carefully into individual rings, saving the small inner pieces for another recipe if they are too narrow to coat.

In one shallow bowl, whisk together the flour, paprika, garlic powder, 1/2 teaspoon kosher salt, and black pepper. In a second bowl, beat the eggs until smooth, and in a third bowl, combine the panko breadcrumbs with the remaining 1/2 teaspoon kosher salt.

Coat each onion ring in the seasoned flour, shaking off the excess. Dip it into the beaten egg, then press it firmly into the panko so the crumbs cover the surface.

For a sturdier crust, dip each ring in the egg and panko a second time. Lightly spray the air fryer basket and arrange the coated rings in a single layer without overlapping.

Lightly spray the tops of the onion rings with oil. Air-fry at 375°F for 5–7 minutes, turn carefully, and cook for another 5–7 minutes, until golden brown and crisp.