How do you add items from other mods to custom villager trades

Im making some custom villager trades and i want to allow the villager to give you tree fertiliser from the create mod in return for emeralds but i don't know how to add it. The in-game item id doesn't work so i was wondering what i would need to replace the bone meal with for it to work? (the bone meal is just a placeholder)

https://www.dropbox.com/s/3g9ljnwgyge3xka/Screenshot%202025-03-09%20at%2017.31.23.png?st=k5vznu2b&dl=0

added a dropbox link to a screenshot cos i cant figure out how to add an image