@rxliuli Thanks, I've got it working on Mac. Great plugin! Joplin even marks all files I've open as being edited externally.
VSCode looks nice too; I'm a Sublime-user, and never seen VSCode before. I'll give it a try for a while, I think.
Note to Mac-users: .md files are opened by Xcode by default, unless you changed that already. You have to do a 'Get info' on a .md file, set 'Open with...' to 'Visual Studio Code' and select 'Change all' on the prompt. Only then, the note-files will be opened in VSCode when you click on them in the plugin.