Place the chicken breast between two sheets of parchment paper and pound to an even half-inch thickness.
In a shallow bowl, whisk together the buttermilk and hot sauce, then submerge the chicken to marinate for at least 20 minutes.
In a separate dish, combine the panko breadcrumbs, garlic powder, onion powder, sea salt, and black pepper.
Remove the chicken from the buttermilk, allowing the excess to drip off, and press firmly into the panko mixture until fully coated.
Lightly mist the breaded chicken with avocado oil and place in the air fryer basket.
Air-fry at 375°F for 12-15 minutes, flipping halfway through, until the coating is golden brown and the internal temperature reaches 165°F.
While the chicken rests, lightly toast the whole wheat bun in a dry pan until warm.
Assemble the sandwich by layering the lettuce, crispy chicken, and dill pickles on the toasted bun.