I made a datapack that adds 5 new structures into your world. When you put it in do /function mine:setup then you will be all ready
If it dose not work then look in the world, if you have not have a folder called generated then move my generated file there, if you do then go inside mine and copy the 5 .nbt filles and put them in the generated files

version 1.0

Abandoned mine,smelter, and arena

added dead miners and smelter skeletons

video on version 1.0
https://www.youtube.com/watch?v=BGYfwgBXQmE&t=16s

version 2.0

added abandoned prison and lab.

added inmates

lucky vest and murky mix

video on 2.0
https://www.youtube.com/watch?v=PnXStohEUWw&t=1s

version 2.1

nerfed lucky vest and buffed murky mix

file renames

no video on 2.1 version

credits

My channel, I have a video on it with other links
https://youtu.be/BGYfwgBXQmE

jragons spawning formula
https://www.youtube.com/watch?v=Uj6zggmU35c&t=39s

mcstacker2
https://mcstacker.net/

Buttloaf, created a structure
https://www.youtube.com/channel/UCZiNMGMZ6ohEBWNtqNCh89w