When I first looked at the website, I thought that it looked like a nice student assignment or a weekend project. But seeing that you are already attempting to monetize this website and that you are treating this somewhat seriously, I have to tell you that your software is lightyears behind the chess opening modules of professional chess software such as ChessBase 15 or Chess Assistant 12.
https://en.chessbase.com/post/announcing-grand-chessbase-15-...
https://chessok.com/?page_id=19894