public class NetworkHelper
{
    /// <summary>
    /// Max attempts after a failed request.
    /// </summary>
    private static int _failedAttempts = 10;

    /// <summary>
    /// Get the html of a page waiting for a specific selector created by an ajax request.
    /// </summary>
    /// <param name="url">Link of the page.</param>
    /// <param name="selector">Selector to wait.</param>
    /// <returns>Html of the web page.</returns>
    public static async Task<string> LoadAndWaitForSelector(Uri url, string selector)
    {
        var browser = await Puppeteer.LaunchAsync(new LaunchOptions
        {
            Headless = true,
            ExecutablePath = Environment.GetEnvironmentVariable("CHROME_PATH"),
        });

        try
        {
            using (Page page = await browser.NewPageAsync())
            {
                await page.GoToAsync(url.ToString());
                await page.WaitForSelectorAsync(selector);
                return await page.GetContentAsync();
            }
        }
        catch (Exception ex)
        {
            //Scale the attempts and retry, server could be busy or the connection goes offline.
            if (_failedAttempts != 0)
            {
                _failedAttempts--;
                await Task.Delay(15000);
            }
            else
            {
                throw ex;
            }

            return await LoadAndWaitForSelector(url, selector);
        }
    }
}

var browser = await Puppeteer.LaunchAsync(new LaunchOptions
{
    Headless = true,
    ExecutablePath = Environment.GetEnvironmentVariable("CHROME_PATH"),
});