Peel potato and cut lengthwise into 1/2-inch sticks. Rinse potato sticks under cold running water for a few seconds. Transfer to a large bowl. Add vinegar and just enough water to cover the potatoes. Let soak for 30 minutes.
Preheat the air fryer to 320 degrees F (160 degrees C).
Drain and pat the potatoes dry. Toss with oil, salt, and pepper in a bowl and transfer to the air fryer basket.
Cook in the preheated air fryer until soft but not browned, about 16 minutes. Shake the basket and raise the temperature to 355 degrees F (180 degrees C). Air fry for 6 minutes, shake, and check for doneness. Cook until outsides of fries are crispy and browned, about 6 minutes more. Taste and adjust salt before serving.