Black to move. Find the one move that wins. About 800 ELO.
From a real ChessLvl game against Yuki Tanaka (LVL 1). Black to move: one move wins.
Something isn't defended. Check what every piece is protected by.
An enemy piece is undefended. Take it for free.
After every opponent move, ask: what did they just leave unprotected?
Before each move, ask what your opponent just left undefended. Free material wins more games than anything else.
Solve it on the board above, or take a hint. Every ChessLvl puzzle is checked by a chess engine to have exactly one best move.