Pretty much the title, I started playing the downloaded version for a while, found out there was a Steam version a bit later, can I transfer my save file to the Steam version?
Quite easy thing - save to file in downloaded version - load from file in Steam version and then just save it there.
En mass - local storage for windows downloaded version is here C:\Users\{user_name}\AppData\Roaming\coc2electron - I don't have steam version but they are probably somewhere like C:\Program Files (x86)\Steam\userdata\{your steamid}\1292690 (I think it is COC2 Steam ID)
One more thing AppData is hidden folder so first you need to show hidden directories.