Snowcapped HELP

Hello, I don’t understand where to put the file generated by Snowcapped.
I see a lot of information saying to put it in
data/minecraft/dimensions/overworld.json
but this file doesn’t exist in version 1.21.8.
I can’t figure out where to put it.
I’ve looked everywhere in the online documentation but can’t find the information.
If someone could help me, I must be missing something.
Where should I put the .json file created by Snowcapped?
How should I properly rename it?
Additional info:
It’s for modifying biome generation.
Thank you in advance!