how to launch vscode live server as a task in launch.json

I need to have vscode to launch vscode live server as a run configuration in launch.json, to be able to include its launch with other run configurations in a compound launch.

I have tried the "Launch Extension" of type "pwa-extensionHost" with several different arguments and runtimeexecutables, for example

    {
      "name": "Launch Extension",
      "request": "launch",
      "type": "pwa-extensionHost",
      "runtimeExecutable": "liveserver"
    }

and

    {
      "name": "Launch Extension",
      "request": "launch",
      "type": "pwa-extensionHost",
      "args": [
        "--extensionDevelopmentPath=${workspaceFolder}",
        "liveserver"
      ]
    }

but couldn't get it run.