Rinse the potatoes under cold running water and dry them completely with a clean towel. Pierce each potato several times with a fork, then coat the surface evenly with olive oil and sprinkle generously with sea salt. Arrange the prepared potatoes in the basket of your air fryer. Set the air fryer to 400°F for basket-style models or 375°F for toaster-style units and cook for 35–45 minutes, rotating the potatoes halfway through. Cooking time will vary based on the potato size; continue air frying until a knife easily glides through the center. Transfer the finished potatoes to a plate using tongs.