If you play web based applications, they have no access to your system`s file system. Mostly saving in web based application is doing with cookie´s.
Try "cookies in chrome" on google for more information. Perhaps you can extract savefiles from there? You can try this tool for looking deeper into the cookies. This link is in german language, but you can easy find comparable tools in other languages. Try "analysing cookies" on google.
https://www.tecchannel.de/a/maxa-cookie-manager-standard-cookies-analysieren-und...
You can find savegame on mac here ~/.godot/app_userdata/yourgame
or perhaps here ~/.local/share/godot/app_userdata
https://godotengine.org/qa/12630/where-does-user-point-to-in-different-os
But in your situation is is easier to start a new game, instead of exporting savefile from a cookie to a mac file.