Preheat your air fryer to 200°C (390°F) and let it warm for about 3 minutes.
Trim the green beans, removing the stem ends, then place them in a mixing bowl.
Drizzle the olive oil over the beans, then sprinkle with salt and garlic powder. Toss everything together until the beans are evenly coated and glistening.
Spread the seasoned green beans in a single layer inside the air fryer basket, making sure they aren’t overcrowded so they can crisp properly.
Cook the beans for 8 to 10 minutes, shaking the basket or stirring halfway through to promote even crisping and browning.
Check the beans; they should be vibrant green with crispy, slightly charred edges and emit a smoky aroma. If needed, cook for an additional 1-2 minutes for extra crispness.
Remove the green beans from the air fryer and transfer to a serving plate. Let them rest for a minute to crisp further.
Serve immediately to enjoy the full crunch and smoky flavor, or sprinkle with additional salt or herbs if desired.