"Where does a wise man hide a leaf? In the forest.
But what does he do if there is no forest? ... He grows a forest to hide it in."
-- Gilbert Keith Chesterton
Ever tried to send a secret message to someone without using the postal service? You could use newspapers to tell your secret. Even if someone finds your message, it's easy...
CheckiO Extensions allow you to use local files to solve missions. More info in a blog post.
In order to install CheckiO client you'll need installed Python (version at least 3.8)
Install CheckiO Client first:
pip3 install checkio_client
Configure your tool
checkio --domain=js config --key=
Sync solutions into your local folder
(in beta testing) Launch local server so your browser can use it and sync solution between local file end extension on the fly. (doesn't work for safari)
checkio serv -d
Alternatevly, you can install Chrome extension or FF addon
checkio install-plugin --ff
checkio install-plugin --chromium