Hello, thank you so much for your comment :D
I am terribly sorry -> as I didnt plan to host a web version initially, there is currently no way of transfering a save file, as the save data is saved quite a bit differently inside your browser.
Soon there will be a free steam playtest, where it will be much easier to download and update the game, the demo will have some additional content there. The local save file will be transferable too! So I highly recommend downloading the game and playing it locally!
Super sorry for the inconvenience!!!