Preheat your air fryer to 200°C (392°F) and prepare a clean workspace.
Trim the ends off the green beans with a sharp knife and pat them dry thoroughly to ensure they crisp up nicely.
Place the green beans in a mixing bowl, then drizzle with olive oil and sprinkle with garlic powder, smoked paprika, and salt.
Toss everything together until the beans are evenly coated with oil and spices, feeling the texture for a slight stickiness and vibrant color.
Spread the seasoned green beans in a single layer inside the air fryer basket, making sure they aren’t overcrowded to allow for even crisping.
Cook for 8-10 minutes, shaking the basket halfway through to promote even browning and prevent burning.
Check the beans; they should be tender inside with crispy, slightly charred edges and smell nutty and smoky.
Once cooked, transfer the green beans to a serving dish and squeeze fresh lemon juice over them for brightness.
Finish with an extra sprinkle of salt or additional spices if desired, then serve immediately for maximum crunch and flavor.