How to rotate the tile?

In Khitan I have not understood how to rotate the tile. I can move it to a neighbour field, but then my turn is already over.
I tried to click several times on the tile in the old position, but nothing happens. grateful if somebody can explain the mechanics of a move. Thanks.
I tried to click several times on the tile in the old position, but nothing happens. grateful if somebody can explain the mechanics of a move. Thanks.