Prepare Cajun tartar sauce. Add all ingredients to a small bowl and whisk well to combine. Cover and place in the fridge for 1 hour prior to serving.
Cut fish into 3” by 1/2” strips. *The easiest way to make these uniform in size that I found was cutting the filet down the center, then cutting each half in half again length-wise, then finally cutting in half width-wise.
Create a dredging station. Add breadcrumbs and shredded parmesan to one bowl. Add garlic powder, black pepper, Cajun seasoning, mayo, sour cream, and Dijon mustard to a separate bowl and whisk to combine.
Dip the fish into the bowl with mayo, then roll in the breadcrumb and parmesan mix. Repeat with all fish sticks.
For easy clean up, line the air fryer basket with parchment paper or foil and place fish inside. If you prefer not to line with anything, that is okay too. Spray fish lightly with canola oil. Depending on the size of the air fryer this may take 2 batches. Do not stack the fish sticks or crowd them!
Set the air fryer to 390 °F (199 °C). Cook for 5 minutes, flip, and cook for 5 more minutes.