Function start_screen_capture_js 

pub async fn start_screen_capture_js(
    source_id: JsValue,
) -> Result<JsValue, JsValue>

__screenStartScreenCapture(sourceId?: string) — Promise<void> (or string error). sourceId is "display-<id>" / "window-<id>" / null for primary display (M-SCK.0.1 / AUT-291).