Preheat your air fryer to 400°F (200°C) to ensure a high-heat environment for maximum crispiness.
Scrub the russet potato thoroughly and slice it into even 1/2-inch thick wedges.
In a medium bowl, toss the potato wedges with 1 teaspoon of olive oil and a pinch of the sea salt, black pepper, and paprika.
Arrange the potatoes in a single layer in the air fryer basket and cook for 15 minutes, shaking the basket halfway through.
While the potatoes roast, whisk together the all-purpose flour, light beer, garlic powder, and the remaining salt, pepper, and paprika in a shallow dish until a smooth batter forms.
Pat the cod fillets extremely dry with paper towels to ensure the batter adheres properly to the surface.
Dip each piece of fish into the beer batter, allowing any excess to drip off, and place them carefully into the air fryer basket next to the potatoes.
Lightly mist the top of the fish with the remaining teaspoon of olive oil and cook for an additional 8 to 10 minutes until the batter is golden-brown and the fish flakes easily with a fork.