You could skip the
chili pepper or
seafood seasoning but I highly recommend using them. It may make the recipe complicated but it will have a closer flavor to squid calamari than an obvious mushroom calamari (especially handy when serving to omnivore family and friends).
You could find Japanese and Korean chili pepper at Asian grocery stores or
online.
You could find Old Bay seasoning at most supermarkets or
online. I prefer Old Bay seasoning but you could use other kinds of seafood seasoning (just double check the ingredients list to make sure it's vegan).
To make the American calamari version, spritz lemon over fried calamari and serve with marinara or tomato sauce on the side.
If serving to kids, serve with vegan mayo instead of vinegar.