On my phone it saves to Download folder. Not www, not www/downoad, not www/downloads
If you can't find the file, use search function on your phone. You know the file name. Open some file explorer app and search for this name.
By the way, when I preview this project on mobile and save the snapshot, Chrome shows me a notification about the saved image and its exact location.
Does it happen on you phone? If not, maybe you are doing something wrong and the snapshot is actually not getting saved.