Preheat your air fryer to 400°F to ensure a hot environment for maximum crunch.
Slice the russet potato into thin wedges and toss them in a bowl with avocado oil, paprika, and a pinch of sea salt.
Arrange the potato wedges in a single layer in the air fryer basket and cook for 15 minutes until the edges are golden.
While the chips cook, whisk together the flour, baking powder, garlic powder, sea salt, and black pepper in a medium bowl.
Slowly pour the cold beer into the dry ingredients, whisking gently until a thick, smooth batter forms.
Pat the cod fillets completely dry with paper towels then dip each piece into the batter, allowing any excess to drip off.
Remove the potatoes and set aside; spray the basket with oil and place the battered fish inside without overcrowding.
Air fry the fish at 375°F for 10 minutes, flipping halfway through, until the exterior is shatteringly crisp and the fish is opaque.