How to install the Woodland spawner data pack:



Place the woodland spawner data pack inside your save's data pack folder


.minecraft > saves > your_save > datapacks



Place the "generated" folder inside your saves folder


.minecraft > saves > your_save



If the data pack is not detected, try one of the following: 



1. type /reload in chat 

2. type /datapacks enable "file/woodland mansion spawner" in chat