In a large bowl, combine the flour, salt, black pepper, garlic powder, paprika, and cayenne pepper. Mix well to ensure the spices are evenly distributed.
Dredge the squid rings in the flour mixture, ensuring they are well-coated. Shake off any excess flour.
Heat the vegetable oil in a large skillet or deep frying pan over medium-high heat. To test if the oil is ready, drop a small amount of the flour mixture into the oil; it should sizzle immediately.
Carefully add the coated squid rings to the hot oil in batches, being careful not to overcrowd the pan. Fry for about 2-3 minutes or until golden brown and crispy.
Use a slotted spoon to remove the squid from the oil and place it on a paper towel-lined plate to drain excess oil.
Once all the squid is fried, transfer to a serving platter, garnish with chopped green onions, and serve with lemon wedges on the side.