It can be fixed, I know chess but a few rules I didn't know about while developing it. I spent 1 week on this project to test the capabilities of AI coding. I didn't want it to take up a ton of time. I will fix all the issues with it at some point in the not so distant future, adding castling as well.
Viewing post in Psychronic Battle Chess MV/MZ Plugin comments
Correction: he spent one week fixing the errors that came about after he effortlessly used an A.I. based plugin generator to do all the coding for him scalping other people's code because this man does not know what effort looks like.
All this is to say is don't bother asking for technical support, as this sock puppet is probably more inept at coding than you are.