Place the onions in a shallow bowl or dish and pour the buttermilk over them.
Let them sit and soak for 1-2 hours.
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 on 390* for about 5 minutes on each side or until they are crispy.
If you prefer, spray with some cooking spray to get them a little bit more brown in color.