auto resign
Your opponent was smart to do that. If you captured or blocked their last pawn from promoting, their best options are to win on time (if they still have a pawn), or to hope for stalemate.
The thing to remember is, if you have an overwhelming advantage, your opponent does not create the stalemate, you do.
As a general rule, you should never resign unless you are 100% certain that your opponent will checkmate you.
Your opponent did not think there was a 100% chance of checkmate, and you proved them correct.
hello chess enjoyers, you try hard, the opponent isn't being serious, and when he has only king and maybe a pawn left he just moves it around until he gets a stalemate.