Convert data pack from 1.20.4 to 1.21.10

Hey,
I'm looking for someone to update the data pack & resource pack to 1.21.10. The original creator is no longer interested in creating/updating data packs  
This is the data pack:
https://modrinth.com/datapack/christmas-datapack
The resource pack is not on the website, but I have it and could send it
Unfortunately, I don't understand anything about how to edit this.