so i made a few custom recipes and only one has worked. the syntax is exactly the same but i just changed the item, name and recipe.
NOTE: the blaze rod recipe works.
Code:
on load:
register new shaped recipe for diamond of mending 1 named "&b&lCompressed Diamond" using diamond block, diamond block, diamond block, diamond block, diamond block, diamond block, diamond block, diamond block and diamond block with id "1"
on load:
register new shaped recipe for blaze rod of mending 1 named "&6&lFire Rod" using blaze rod, diamond block, blaze rod, netherite ingot, blaze rod, netherite ingot, blaze rod, diamond block and blaze rod with id "1"
NOTE: the blaze rod recipe works.