Hi.

The Epic Games Store version stores the save file at:
C:\Users\InsertName\Documents\Journey

The Steam version stores it at:
C:\Users\InsertName\AppData\Local\Annapurna Interactive\Journey\Steam

In both cases, it'll be named SAVE.bin

Just copy the file from the Documents folder to the AppData folder and everything will transfer over.

I personally didn't get any issues, but I'd recommend making a backup of the Steam file before you copy it over. Just in case.

I've not done this whole guide thing before, but I figured it'd save some people a couple minutes of googling.