Use selenium to get the paging token, do post to youtube and parse the video list from response

selenium-get-youtube-videos-paging.cs

class Program
    {
        static void Main(string[] args)
        {
            using (var driver = new FirefoxDriver())
            {
                driver.Url = "https://www.youtube.com/results?search_query=m%E1%BB%B9+t%C3%A2m";
                var wait = new WebDriverWait(driver, timeout: TimeSpan.FromSeconds(30))
                {
                    PollingInterval = TimeSpan.FromSeconds(5),
                };
                wait.IgnoreExceptionTypes(typeof(NoSuchElementException));

                var content = wait.Until(drv => drv.FindElement(By.TagName("ytd-video-renderer")));

                IJavaScriptExecutor js = driver as IJavaScriptExecutor;

                var continuationToken = (string)js.ExecuteScript("return window.ytInitialData.contents.twoColumnSearchResultsRenderer.primaryContents.sectionListRenderer.contents[0].itemSectionRenderer.continuations[0].nextContinuationData.continuation");
                var clickTrackingParams = (string)js.ExecuteScript("return window.ytInitialData.contents.twoColumnSearchResultsRenderer.primaryContents.sectionListRenderer.contents[0].itemSectionRenderer.continuations[0].nextContinuationData.clickTrackingParams");

                //Prepare headers
                var uagent = js.ExecuteScript("return navigator.userAgent;");
                var cookies = driver.Manage().Cookies;                
                var INNERTUBE_CONTEXT_CLIENT_VERSION = (string)js.ExecuteScript("return ytcfg.data_.INNERTUBE_CONTEXT_CLIENT_VERSION;");                

                var httpClient = new HttpClient();                
                httpClient.DefaultRequestHeaders.Add("X-YouTube-Client-Name", "1");
                httpClient.DefaultRequestHeaders.Add("X-YouTube-Client-Version", INNERTUBE_CONTEXT_CLIENT_VERSION);
                httpClient.DefaultRequestHeaders.Add("user-agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.116 Safari/537.36");
                                
                var url = $"https://www.youtube.com/results?search_query=m%E1%BB%B9+t%C3%A2m&pbj=1&ctoken={continuationToken}&continuation={continuationToken}&itct={clickTrackingParams}";
                var response = httpClient.GetAsync(url).Result;
                response.EnsureSuccessStatusCode();

                string result = response.Content.ReadAsStringAsync().Result;
                //Parse the video list from result


                Console.WriteLine(result);
                Console.ReadLine();
            }
        }        
    }