I have used non-alcoholic beer here, but you can use any regular beer or in case you don’t want to use any kind of beer, try Soda water ( sparkling water ) and Yeast. Even in any case you don’t have the Yeast, just Soda water should be fine.
Use hot oil while frying the fish, The fish should be ready in less than a min. When you put the fish in hot oil the outer later will become very crispy and fluffy.