Place the onions in a shallow bowl or dish and pour the buttermilk over them.
Let them sit and soak for 1-2 hours.
Just before cooking, coat the basket of the air fryer with grapeseed oil spray or line with parchment paper or foil. If lined, be sure there is room on the sides for air to circulate.
Prepare a bowl for the flour, a separate bowl for beaten eggs, and another bowl for the breadcrumbs.
Add a dash of salt to the breadcrumbs.
Dip the onions in the flour, dust off any excess.
Dip them in the eggs, let the excess drip off.
Coat with the breadcrumbs.
Place evenly in the Air Fryer.
At this point, you can add some salt to them or salt them after they are done.
Fry them in the Air Fryer at 390°F for about 5 minutes on each side or until they are crispy.
If you prefer, spray with some grapeseed oil spray to get them a little bit more brown in color. This is what will get rid of any floury texture.
Serve.