If using wooden skewers, soak them in water for at least 20 minutes to prevent burning.
In a large bowl, whisk together the olive oil, soy sauce, worcestershire sauce, minced garlic, smoked paprika, onion powder, black pepper, and salt. Add the steak cubes and toss to coat. Let them marinate for at least 15 minutes, or up to 2 hours in the fridge.
Thread the marinated steak cubes onto the skewers, alternating with pieces of red bell pepper, green bell pepper, red onion, and mushrooms. Pack them snugly but not too tightly so everything cooks evenly.
Preheat the air fryer to 400°F (200°C) for 3 minutes.
Place the kabobs in the air fryer basket in a single layer. You may need to trim the skewers to fit. Air fry at 400°F for 10 to 12 minutes for medium, turning them every 3 to 4 minutes so all sides get nice color.
Remove from the air fryer and let the kabobs rest for 3 minutes before serving. The steak will be juicy and caramelized with perfectly tender vegetables.