The traditional flavor of Sichuan fish is fried garlic with pickled peppers in Sichuan, and Pixian bean paste can be used instead of pickled peppers.
If you don't want to use bean paste, you might as well use ordinary Chili sauce bought in the market with ketchup. Mainly fried garlic, add these sauces, the proportion of soy sauce and sweet and sour should be appropriate, and finally there is chopped green onion.