How to connect VS Code via FTP with Remote Workspace?

I have embarked on my Visual Studio Code odyssey. I need to use it to edit files on a remote FTP server. I installed the Remote Workspace extension (vscode-remote-workspace)

Instructions say:

Create (or update) a .code-workspace file and open it by using File >> > Open Workspace... in the GUI:

{
    "folders": [{
        "uri": "sftp://my-user:my-password@example.com?debug=1",
        "name": "My SFTP folder"
    }]
}

like...

FTP [↑]
URL Format: ftp://[user:password@]host[:port][/path/to/a/folder][?param1=value1&param2=value2]

{
    "folders": [{
        "uri": "ftp://my-user:my-password@ftp.example.com/",
        "name": "My FTP folder"
    }]
}

I am trying to set up a connection to my FTP server.

I have:

• Saved Workspace As to create MySpace.code-workspace file
• Opens Settings and pasted the following in to Workspace Settings...

{ "folders": [{ "uri": "ftp://myuser:mypass@ftp.myhost.com:21", "name": "My FTP folder" } ], "settings": {}, }

However, the bottom-right of VSCode reports...

("Can't find remote", "File not found")

... while the sidebar shows...

(An exclamation mark, with the hint underneath hover: "Can not resolve workspace folder")

I don't get to see any file tree, though I have read the parallel issue about a problem showing files below top level.

I wondered if my FTP host has trouble accepting a login with the uri format you advise. Trying to login to it via Mac Terminal with myuser:mypass@ftp.myhost.com:21, it actually reports: 331 User myuser:mypass OK. Password required, which is obviously wrong. It took removing the password and port to login to it via Terminal. But doing so in Code Workspace Settings doesn't work either.

How can I overcome this?