Uses the Stockfish chess engine. My own code for recognising human player move and moving robot arm.
See my Instructable: https://www.hackster.io/ricpd/scara-chess-robot-a45793
I have subsequently made one which uses a discarded phone and so does not require a processor, camera, screen and keyboard: https://github.com/rpd123/chess-robot/tree/main/versiongui