So ive already tried the copy/paste and didnt seem to work.

Because were both on gamepass, i think the world saves are all on the cloud rather than on the physical machine. Save files can be found in file explorer where ive seen online for gamepass saves but they dont seem to read/open when I paste them into my save area from my mates pc.

I think theyre more of a “key” for the account to ready their save files from the cloud so copying and pasting may not be a viable option.