Preheat your air fryer to 350 degrees Fahrenheit.
Slice your eggplant into thick rounds, about half an inch thick, and make slits in the middle of each slice.
In a shallow bowl, combine avocado oil, white sugar, low sodium soy sauce, minced garlic, and chili oil (if using).
Line your air fryer basket with parchment paper.
Place your sliced eggplant rounds in a single layer in the air fryer basket and spoon the marinade over each piece.
Air fry your eggplant at 350 degrees Fahrenheit for about 15 minutes, switching on the broiler for an additional two minutes if you prefer a crispier texture.