The [**official guidance**][1] is to use the [**`runtimeArgs`** attribute][2] like this:

```json
{
    "name": "Launch Program",
    "request": "launch",
    "type": "node",
    "runtimeArgs": ["--experimental-modules"],
    "program": "${workspaceFolder}\\bin\\www"
}
```

Which will run the following terminal command:

```bash
node.exe --experimental-modules .\bin\www
```

**See Also**: [How to start nodejs with custom params from vscode][3]


[1]: https://code.visualstudio.com/docs/nodejs/nodejs-debugging#_how-do-i-debug-ecmascript-modules
[2]: https://code.visualstudio.com/docs/nodejs/nodejs-debugging#_launch-configuration-attributes
[3]: https://stackoverflow.com/q/29968919/1366033

I can run my node.js application with `es6` modules with the `--experimental-modules` flag as follows:

    node --experimental-modules ./bin/www

How can I do the same when debuggging the application from VS Code, which uses the launch.json configuration file? 

    {
        "version": "0.2.0",
        "configurations": [
            {
              "type": "node",
              "request": "launch",
              "name": "Launch Program",
              "program": "${workspaceFolder}\\bin\\www",
            }
        ]
    }