Thank you for the tutorial! I’ve just had a go at it and got it to work. I think there might be a typo in your description though - it says to put the text for the book in the ExtraData attribute of the key. I tried this but the content didn’t appear when I’d finished the other steps. If I put the text for the book in the Content attribute it works nicely though.

Your tutorials are really helpful, I hope to see more!