how do i even make nether features even spawn? (2024.4)

I still haven't gotten the answer but all I have to say is this:

I'm trying to make a hollow earth dimension that generates like the nether

I made an ancient mahogany tree and tropical conifer tree (both are structures files instead) but neither of them spawn

here is the generation list for the ancient mahogany tree (may also get started on the lore of the mod soon!)

repeated: number between 2 to 6

within a random XZ within chunk

on heightmap: motion blocking

only if condition:

list of conditions:

1. solid block underneath
2. solid block is a grass block

only if biome in current has this feature

also trying this out I tried to go with the offset by -18 but that maybe a problem i will check out than come back to update it