Rinse the shishito peppers and pat them thoroughly dry with a paper towel to ensure proper blistering.
In a medium mixing bowl, toss the peppers with olive oil and sea salt until evenly coated.
Preheat the air fryer to 400°F (200°C).
Place the seasoned peppers in the air fryer basket in a single layer to allow for maximum airflow.
Cook for 7 to 9 minutes, shaking the basket halfway through the cooking time, until the peppers are tender and the skins are blistered and charred in spots.
Transfer the peppers to a serving plate, drizzle with lemon juice, and garnish with sesame seeds if desired.