In a mixing bowl, whisk together avocado oil, sesame oil, fish sauce, minced garlic, maple syrup, coconut aminos, sriracha (if using), and rice vinegar until combined; this should yield about 1 cup of marinade.
Reserve roughly 1/3 of the marinade in a separate container for serving as a dipping sauce later.
Place the chopped chicken pieces in a zip-top bag or sealable container and pour in about 2/3 cup of the remaining marinade. Seal and move the bag or toss the container until the chicken is fully coated.
Marinate the chicken in the refrigerator for at least 20 minutes, or up to 24 hours for more flavor.
Preheat the air fryer to 375°F (190°C) for 3–5 minutes.
Arrange half of the chicken in a single layer in the air fryer basket (cook in batches if needed). Air fry at 375°F for 8–12 minutes, shaking the basket or flipping pieces halfway through, until the chicken is cooked through and reaches 165°F.
Remove the cooked chicken bites, then repeat with the remaining chicken if you cooked in batches.
Serve the chicken bites hot with the reserved marinade as a dipping sauce; season with sea salt and black pepper to taste.
