In a bowl, mix together the cream of mushroom soup, with milk, and soy sauce. Then, mix in the green beans. Finally, mix in 2/3 cup of french fried onions.
Place the mixture in an oven safe dish that fits in your air fryer basket (like the cake barrel air fryer casserole or air fryer silicone pot).
Air fry for 8 minutes at 350 °F. Add another 2/3 cup of onions to the top of the casserole and cook for an additional 2 minutes.