If you're using frozen fish, make sure to thaw it completely before starting. Then, pat the fish fillets dry with paper towels.
Next, slice the fillets lengthwise into strips approximately 4cm x 9cm (1 ½" x 4"). For example, if you're using cod fillets, you can divide each one into 4 strips, resulting in a total of 16 strips.
Season the flour with salt and pepper, and spread it out on a shallow dish. In a separate bowl, whisk the eggs, and place them next to the dish with flour.
Take another shallow dish and put the breadcrumbs in it, setting it beside the bowl with eggs.
Now, dunk each fish piece into the flour mixture, shaking off any excess flour.
Then, dip the flour-coated fish into the whisked eggs, followed by covering them with the breadcrumbs. Ensure each piece of fish is fully coated at each step. You might need to wash your hands once or twice during this process.
Once the fish sticks are thoroughly coated, drizzle or spray a little oil on them.
Place the fish fingers in the Air Fryer basket in a single layer, without overlapping them.
Cook them at 200 °C (400 °F) for 10 minutes, flip them, and then cook at 240 °C (480 °F) for another 5 minutes.