Open the bag of frozen green beans and dump them into the basket of your air fryer. Shake around so they are evenly distributed.
Air fry the green beans at 350 degrees F for 10 minutes.
Meanwhile, place the soy sauce, butter and brown sugar into a microwave-safe dish. Microwave on high power for about one minute. Give the mixture a stir to make sure it is all melted together.
Transfer the air fried green beans to a clean bowl. Toss them with the soy sauce glaze. Serve immediately.