Preheat your air fryer to 400°F (200°C).
Cut the potato into thin wedges and toss them in a bowl with 1 teaspoon of olive oil and a pinch of sea salt and black pepper.
Place the potato wedges in the air fryer basket in a single layer and cook for 15 minutes, shaking halfway through, until golden and crisp.
While the potatoes cook, whisk together the flour, baking powder, garlic powder, paprika, sea salt, and black pepper in a shallow bowl.
Slowly whisk the cold light beer into the dry ingredients until a smooth, slightly thick batter forms.
Pat the cod fillets completely dry with paper towels and lightly brush them with the remaining 1 teaspoon of olive oil.
Dip each cod fillet into the beer batter, allowing any excess to drip off, and place them carefully into the air fryer basket.
Reduce the air fryer temperature to 380°F and cook the fish for 10-12 minutes until the coating is golden-brown and the fish flakes easily with a fork.