The plugin TECHNICALLY has options for "adding a recipe to an existing book," which you can trigger at a certain level; But it never seemed to work for me. So I made a worked around: just add an extra item.
Ex. The base book (key item) includes items a-e.
At level 15, they gain a...
Update: I was able to figure it out (except for the sound effect; don't know enough about java to know where exactly to type it in, but that's not a big deal.)
The neat thing that Rohsek's tweak also allows: you can now pull out the book to check the recipes without allowing people to craft...
Not about my game project but i feels like to talk about it a bit.
It's my コテキャ and maybe closest thing in english is a "avatar personality" i guess?
Her design also looks very similar to protagonist from my game because i'm so uninspiring
Oh and my hobby is sleeping and drawing.