Combine mayonnaise, relish, and seafood seasoning in a large bowl. Add fish and gently stir to coat.
Preheat an air fryer to 400 degrees F (200 degrees C).
Place bread crumbs on a plate. Coat each fish stick in bread crumbs 1 at a time.
Place fish sticks in a single layer in the basket of the air fryer, making sure none are touching. Cook for 12 minutes. Remove the basket and let rest for 1 minute before transferring fish sticks to a paper towel-lined plate. Repeat with remaining fish sticks.