Click and drag the squares, fit them into the hole. There is an extra mechanic though, Called Square grouping. Hold M1 and hover over multiple squares at once and they all go onto your cursor. This is supposed to make up for the hindered ability pc players have in these types of games.
Warning: Square grouping will sometimes have a louder sound than others. I have no idea how it occurs, and frankly, I'm too lazy to fix it.
