Black moved last. What was Black's last move & what was White's?
There are, at least, 3 solutions.
Since black moved last and is now on h1 the last move by black must have been h1, or possibly a capture of a piece on h1 (was that a question??). White's last move was probably b8(B) promoting a pawn and giving check. White must next move e1 or e2 or h2 else stalemate. (This assumes white is on the bottom of the diagram. Otherwise f1 must have been white's last move.) My chess is rather rusty, but the position seems absurd.