draw conditions
The rook stops the king from moving to the 3 available squares on the a file. The queen on e8 stops the king from moving to b5 or b6 leaving only the available spaces b7 and c7 and c5. When you promoted to queen it took away b7 and c7 and c5. The king is not in check and is unable to move. This is called a stalemate.
I'd suggest looking up the concept of Ladder Mates. On move 42 you could have played 42.c8=Q+ and between the 2 Queen-and-Rook pairs that you have, mate would have come very quickly. If you learn this along with King and Queen vs King checkmates, you will be able to end the game quickly.
In the future, when you have a large material advantage, always pay attention to how many legal moves that the opposing king has. Players at the beginner level are encouraged to not resign so they will always be playing on to hope to get a Stalemate in this type of position.
I am a beginner at chess and might not know the rules but the situation below was considered to be a draw by the system. why? What am I getting wrong?