You will need 3 small bowls. Place flour in one bowl, eggs and milk in a second bowl (beat them together) and then the Panko crumbs in a third bowl.
Coat the sliced onions in the flour, then in the egg mixture and then in the bread crumb mixture. Place on a separate plate until ready to air fry.
Continue to do this until all of the onions have been coated.
Preheat the air fryer to 400 degrees F. *Note: If your air fryer does not have a preheat option than run your air fryer at 400 degrees F for 5 minutes to heat up the air fryer.
Place the coated onions in the air fryer in a single layer (do not overlap), spray the tops of the onions with oil spray to make them brown when they cook and cook at 400 degrees F for 7-10 minutes until your onions are cooked to the crispiness that you prefer.
Serve topped with salt with your favorite dipping sauces.