Extension load error

[ParadiseDS]

After reviewing the loading extension code I thought the extension syntax in setting files is
extensions: ['tables', 'fenced_code']
But when I write the setting into User-settings, ST3 alert me that it expects value in the bracket, which means it cannot parse content in ' as a value. I just ignore it and run the command, but the extension seems not to work in the slide. I didn't know whether ST3 pass the extension parameters to the package or not or there's other issues making extension not work.