Preheat the air fryer to 400°F for 3–5 minutes.
In a large bowl, toss the potato cubes with 2 teaspoons olive oil, garlic powder, onion powder, salt, and black pepper.
Add the seasoned potatoes to the air fryer basket in a single layer.
Cook at 400°F for 10 minutes, shaking the basket halfway through for even browning.
Add the diced bell peppers and yellow onion to the basket and drizzle or toss with the remaining 1 teaspoon olive oil.
Continue cooking for 8–10 minutes, shaking once, until potatoes are golden and crispy and peppers are slightly tender.
Taste and season with additional salt and pepper as needed. Serve immediately.