Place chicken tenders in a shallow dish or zip-lock bag. Pour pickle brine over them until fully submerged. Cover and refrigerate for 6–24 hours. (Overnight is ideal.)
Remove tenders from brine and pat completely dry with paper towels on all sides. Don't skip this step.
Preheat air fryer to 400°F (200°C) for 5 minutes.
Set up three shallow dishes: flour in the first, beaten eggs in the second, and panko mixed with paprika, garlic powder, onion powder, salt, and pepper in the third.
Dredge each tender in flour (shake off excess), dip in egg (let excess drip), then press firmly into seasoned panko to coat all sides.
Spray the air fryer basket with cooking spray. Arrange tenders in a single layer. Spray the tops generously with cooking spray.
Air fry at 400°F for 5–6 minutes. Flip each tender, spray the tops again, and cook for another 5–6 minutes until golden and crispy.
Check internal temperature — it must reach 165°F (74°C). Rest for 2–3 minutes before serving.
Serve immediately with your favorite dipping sauce.