APOLOGISE-in mate in two

hey, I tried to make some moves but whenever I click on a piece I get a black banning circle and I can't move anything.
Does anyone know why ? Maybe because I use Mozilla Firefox ?
a trick in puzzles seems to be to work out your forced mate first, and then add pieces to create a random mate in one to the other side. it adds nothing to the problem (which is to find the forced mate), but makes the whole thing look more dramatic (it probably actually makes the puzzle easier, because you know every move move must be a check, but it looks good).