you can now generate recipe jsons using minecrafts inbuilt data generators in 1.14
i know its been a while since you posted this but i can make the mod for you if you still want it?
just add jei to mods file that forge created
Its not different to how you create normal blocks at all
on the second line of your serverstart.bat add pause so you can see whats wrong
I'm not sure if that's possible in 1.13/1.14.