I’m on the Microsoft Store version. It’ll be different for Steam.
For mine all I have to do is copy everything in the ‘Onestore’ folder that’s in the ‘Official’ folder to the new machine.
When installing on the new machine you’ll probably need to start the set up so it creates the folder strucuture, then stop soon after, delete what’s already in the Onestore folder and do your paste.
The new machine will start up like it’s always been there.
It’s a great relief this is possible with this game, as it doesn’t work for most other Microsoft stuff. It would be the best part of a week to redownload for me.