driveLetter:\Users\pcUsername\AppData\Roaming\coc2electron
I think the autosaves will also be in the "blob_storage" folder (as that's where the saves in-game are stored - as blob files).
If you want to delete all your progress (saves and CG's seen) you can just delete the folders in the "coc2electron" directory, however, doing so removes all of the custom settings for the game as well (such as if you had Dark Mode enabled it won't be anymore) - so you'll have to redo that.