whats the code for the book
Do you mean an answer to the puzzle, or how the symbol can be showed?
If it's the first one, I can't tell you here as it is a spoiler and it would be a bit disrespectful towards the developer to show the answer to his puzzle on the public. A little hint : look at the table.
If it's the second one, I have no idea. If neither, please clarify me.