I am using pypeeter for a web scraping project,

I have several page.evaluage functions and works fine,

but whenever I run await page.evaluateOnNewDocument(js_statement)

js_statement ="""
                        () =>{
                            Object.defineProperties(navigator,{ webdriver:{ get: () => false } });
                            window.navigator.chrome = { runtime: {},  };
                            Object.defineProperty(navigator, 'languages', { get: () => ['en-US', 'en'] });
                            Object.defineProperty(navigator, 'plugins', { get: () => [1, 2, 3, 4, 5,6], });
                         }
                    """

I get only None, kindly help.