Update app.py

app.py

@@ -59,7 +59,10 @@ def btn_play(inp_fen, inp_move, inp_notation, inp_k):
     else:
         mv = chess.Move.from_uci(predict_move(board.fen(), top_k=inp_k))
     
-    board.push(mv)
+    if mv in board.legal_moves:
+        board.push(mv)
+    else:
+        raise ValueError(f'Illegal Move: {str(mv)} @ {board.fen()}')
         
     with open('board.svg', 'w') as f:
         f.write(str(chess.svg.board(board, lastmove=mv)))