Place flour and ranch seasoning mix onto a large plate and whisk to combine.
Crack eggs onto another large plate and whisk until combined.
Place breadcrumbs, parmesan, 1/2 teaspoon salt and 1/2 pepper pepper onto a third large plate and whisk to combine.
Working with one filet at a time, season with salt and pepper, to taste, then fully cover the filet in the flour/ranch mixture (don’t be shy, this gives a lot of flavor), then whisked egg, and then panko/parmesan mixture.
Season with more salt and set aside on a clean work surface.
Repeat with remaining filets.
Preheat air fryer to 350 degrees F.
Grease air fryer basket with cooking spray and place in 2 of the prepared filets.
Spray the tops with cooking spray and cook for 8-10 minutes, flipping halfway through, or until the fish is cooked through.
Remove from air fryer, repeat with remaining 2 filets, and serve with lemon garlic aioli as a dipping sauce.