Why is this a brilliant move?

Missed this and still can’t figure out why this was awarded as brilliant. ELO ~600

This game was all theory

Last 1 second Mate in 1.

ELI5 why brilliant?

guys what i do with the daily puzzle, what funny move could it possibly be 😭

Why did white surrendered here?

White blundered the fork, but luckily has one line to keep things equal. What is it?

FINALLY

Took me an absurd number of games. I have no idea what time format the bot’s elo is based on, but it sure is strong.

Why was this a blunder?

What's the meaning of these numbers that I've highlighted?

And why are the 22nd and 23rd move numbered differently? This is from analysis on Lichess.

Why is this marked as brilliant ? I pressed show moves and I don’t see anything good.