It is the daily puzzle posted from lichess on their mastodon account 6h ago. https://mastodon.online/@lichess/111040949263111774
Because white doesn't have to take the knight first. White can trade queens there, and then the knight is lost on the next move.
N = Knight, F4 = square moved to, + = opponent King in check, # = Opponent King in Checkmate
Algebraic notation
Wouldn't the bishop just take the knight?
The king is in check so that isn't an option.