Preheat your air fryer to 375 degrees F (190°C) for a few minutes, or use the preheat button. This ensures it's hot and ready for cooking the onion rings.
In a separate bowl, whisk together the buttermilk, beer, and eggs.
Combine flour, paprika, garlic powder, cayenne pepper, and salt in a bowl. In the third bowl, add the panko breadcrumbs.
Dip each onion ring into the flour mixture first, then into the buttermilk, beer, and egg mix, and finally, coat it well with Panko breadcrumbs. Place the breaded onion rings on a plate.
Carefully place the beer-battered onion rings in a single layer in the preheated air fryer basket. Do not overcrowd; you may need to cook them in batches.
Cook the onion rings in the air fryer for approximately 10-12 minutes, flipping them halfway through the cooking time. This ensures even browning and crispiness.
The onion rings are done when they turn a deep golden brown and have a crispy texture. You can cook them for an additional minute or two for extra crispiness.