Coat air-fryer basket with cooking spray. Preheat air fryer at 375°F. In a large bowl combine soy sauce, ginger, garlic, and crushed red pepper. Transfer half of the soy mixture to a medium bowl. Stir in bell peppers, onion wedges, and oil. Add ground beef and/or pork, chopped onion, and bread crumbs to reserved soy mixture in large bowl; mix well. Shape into 12 meatballs.

Arrange meatballs in prepared air-fryer basket. Arrange bell pepper mixture around meatballs. Cook 15 minutes or until meatballs are done (160°F), turning meatballs and stirring bell pepper mixture once. Top servings with green onions and, if desired, serve with rice.