Peel the onion and slice into thick rings, separating them carefully.
In a medium bowl, whisk together the chickpea flour, garlic powder, smoked paprika, sea salt, and black pepper.
Slowly pour the light beer and egg whites into the flour mixture, whisking until a smooth, thick batter forms.
Lightly coat the air fryer basket with avocado oil and preheat to 375°F.
Dip each onion ring into the batter until fully coated, then place in a single layer in the air fryer basket, working in batches if necessary.
Air fry for 10-12 minutes, flipping halfway through, until golden and crisp.
While the rings cook, stir together the Greek yogurt, lemon juice, and fresh chives in a small bowl to create the high-protein dipping sauce.