For extra flavor, try using a flavored panko bread crumb, such as Italian or garlic. If you don't have grill seasoning, you can substitute with a combination of paprika, garlic powder, onion powder, and a pinch of cayenne pepper. Be sure not to overcrowd the air fryer basket. Cooking in batches ensures even cooking and maximum crispiness. These onion rings are best served immediately while they are still hot and crispy.