Preheat the air fryer to 400°F (200°C) for about 5 minutes.
In a large bowl, combine the steak cubes, olive oil, garlic powder, onion powder, smoked paprika, salt, and pepper. Toss until the steak is evenly coated.
Place the seasoned steak bites in a single layer in the air fryer basket. You may need to do this in batches depending on the size of your air fryer.
Cook the steak bites for 8-10 minutes, shaking the basket halfway through, until they reach your desired level of doneness (medium-rare is about 135°F).
While the steak is cooking, mix the melted butter with the minced garlic in a small bowl.
Once the steak bites are done, remove them from the air fryer and drizzle the garlic butter over the top. Toss to coat.
Serve immediately, garnished with fresh parsley if desired.