Backporting a 1.21.5 structure datapack to 1.20.1

Hello! I've been working on a modpack for a server with friends, and I've decided to go with several structures from "Dungeons and Taverns" to replace vanilla structures. However, some of the structures I'd like to use are only made for 1.21+. I've been able to figure out most of them, but I'm having trouble backporting the Nether Fortress Overhaul. Admittedly, I have very little experience with datapacks so I'm not sure what I actually need to look for in order to backport it. So far, I've figured out renaming /nova_structures/loot_table and /nova_structures/structure to /nova_structures/loot_tables and /nova_structures/structures respectively, but that isn't enough to have it validate when I want to add it to the modpack. Anyone have any pointers as to what I need to do in order for this to work? Thanks!