There are several sites where one can analyse his/her game. I often use lichess at the end of a game to see where I made mistakes. What I miss, though, is some kind of explanation of why a certain move was a mistake and why another one was better. Where can one find this kind of feedback that is not limited to good/bad but includes a reason?
https://decodechess.com/ advertises this kind of service but I doubt if it's really useful.
Computers are great at finding mistakes, but awful at giving reasons. The best they can do is giving you a continuation you can follow through, but it's ultimately you the one who will have to translate it into human language. That's why computers are a tool to assist chess training, not a replacement for actual trainers.