Type a slash to show the board, then the letters that you want pressed. When a letter appears on both sides of the board, use uppercase for the left and lowercase letter for the right.
For example, /PHRUFr displays as /PHRUFr. Try typing in the box below. Don't forget to start with a slash to draw the board.
This is an ordinary truetype font: stenoboard.ttf. I'll be tidying up the key shapes later; this is just a proof of concept.