Peel and slice the sweet onion into half-inch thick rings, separating the layers carefully.
In a medium bowl, whisk together the egg whites, light beer, chickpea flour, garlic powder, and smoked paprika until a smooth, bubbly batter forms.
Lightly grease the air fryer basket with avocado oil and preheat the air fryer to 375 degrees Fahrenheit.
Dip each onion ring into the batter, allowing excess to drip off, then place in a single layer in the basket.
Air fry for 10 to 12 minutes, flipping halfway through, until the coating is golden and crispy.
While the rings cook, stir together the Greek yogurt, sriracha, sea salt, and black pepper in a small bowl to create the zesty dip.
Serve the hot onion rings immediately with the chilled dip on the side.