You don't need to in the demo. It's not a requirement for any task.
i just had the same problem, i had over 40 ectoplasym and i tried using the book at every time of day and it wouldn't let me, so idk if its a bug on some playthroughs
edit: i found out how to do it, you have to go into the menu and the book icon where it tells you the requirements then press confirm ruitual