AK-33:
The instruction is for white to play, but it's actually black's turn.

WJTetley:
Can the description please be updated as to which color is playing first? It would be of great help in knowing which spot to play first.

rpablo007:
Which color is to play seems to really matter, because black can play B13, but white can't; black can play at J13, but white can't; white can play at D13 but black can't. So, the moves change a lot depending on which turn is to play.

garyleung:
The question does not indicate whether it is black’s or white’s turn.

StephaneLamy:
After L12 B13, D13 should not be incorrect