I think it supposed to be a win for AntiChess

From the rules I know for AntiChess, you can also win if you got checkmated. What do you think?

Nope, the rules (at least for Lichess) say that the king is just another piece. To win, you have to get stalemated, or your opponent has to take all your pieces.

I know that, but I'm asking why wouldn't it be a win?

you are probably thinking of a closely related variant where the king and checks are still respected (you also cannot promote to kings), some use the term "loser's chess" to refer specifically to that variant. it results in games that are actually legal in standard chess.

that's not what we got here.
this is "suicide"/"giveaway"/whatever, the king has no special meaning and you can even promote to kings.

If you played the game on this site, why did you import it rather than link to it directly?

lol I didn't play this game, I was reading about Antichess on the internet and found that many places said that being checkmated is a win. So I just created a game where you get checkmated.