Preheat your air fryer to 400°F to ensure a crisp finish.
Slice the russet potato into thin wedges, pat dry with a paper towel, and toss in a bowl with half of the olive oil and half of the sea salt.
Arrange the potato wedges in a single layer in the air fryer basket and cook for 15-18 minutes, shaking halfway through, until golden and tender.
While the chips cook, whisk together the flour, beer, garlic powder, and paprika in a shallow bowl until a smooth, thick batter forms.
Pat the cod fillet completely dry, season with the remaining salt and black pepper, then dredge thoroughly in the beer batter.
Lightly grease the air fryer basket with the remaining oil, place the battered cod inside, and air fry at 375°F for 10-12 minutes until the coating is crispy and the fish flakes easily.