Edit > Setup Position
Use this dialog box to start a new game with a setup position.
Select a piece from the piece bar on the right. Click a square on the board to put the piece there. Click again to remove the piece.
Specify which side is To move: White or Black.
Specify the Move number of the first move (move number is 1 by default).
Select Clear board to remove all pieces from the board.
Select Reset to show the start position of a game.
Select Mirror to mirror the position.
Leaving the board empty is allowed. In that case you cannot execute moves but you can add graphic commentary.