When using the FileZilla client as an application directory (link), I can right-click an html file on a remote server → View/Edit and it will open in my predefined editor (e.g. VSCode).
BUT if I use the FileZilla flatpak version, then I get the following error:
The file 'index.html' cannot be opened: The associated program (/usr/bin/code) could not be found. Please check your filetype associations.
I can run
/usr/bin/code from the command line, but it doesn't work with FileZilla.