How is this a castling move ?
It is possible because the game you are talking about is Chess960 variant and the starting square of the King can vary.
https://support.chess.com/article/347-chess960-fischer-random-chess
It is possible because the game you are talking about is Chess960 variant and the starting square of the King can vary.
https://support.chess.com/article/347-chess960-fischer-random-chess