Preheat your air fryer to 200°C (390°F) for about 3 to 5 minutes.
If desired, place popcorn kernels to a bowl and coat with 1 teaspoon of oil. The oil is not necessary, but it makes popcorn lighter and tastier.
Line the base of the air fryer basket with aluminum foil, then add popcorn kernels and spread out in a single layer for even cooking. Do not overcrowd the basket.
Air fry popcorn for 8 to 10 minutes. Once the popping slows down to about 1 second, the popcorn is ready. Turn off the air fryer and wait about a minute before removing the basket. This prevents the popcorn from popping out of the air fryer.
Remove the basket and add popcorn to a bowl with salt and seasonings of choice. You can serve immediately, or let the popcorn cool and store in an airtight food container at room temperature for up to a week.