If you cook pickled fish, I suggest that you can simply thicken white flour with water and then add egg white. I can't say that it is much better than starch, but the final result is ok. I have done this myself. Also, if you are pickling fish fillets, it is not recommended to use flour, because flour is easy to come off, so the cooked fish will look sticky. If there is no starch at home, just add a proper amount of egg white.
The dishes made of powder are crystal clear, bright and shiny, and they look very appetizing. But flour is different. I used flour to replace it once, and as a result, the food turned into paste, and the flour was sticky on the food, which was very unsightly. So experience tells me that you can't use a thin layer of even flour, you can fry it in the oil pan until it is golden on both sides.
If there is more flour left in the plastic bag, you can save it for cooking fish next time and don't waste it, but it's best not to add too much flour at a time. If it's not enough, it's better to add it once. If you eat sweet and sour fish, it's better to use starch for pickled fish, especially for fish fillets with pickled fish. Starch and egg white are used, and the fillets are much smoother. It's best not to use flour instead of starch for this dish. If you really don't have it at home and don't have time to go out to buy it, if you really can't find starch at hand, use flour and baking powder! Adding baking powder, the flour will swell when fried, and the effect is similar to that of adding starch, but it is not so brittle. Use aluminum-free baking powder!