Excluding internal traffic in Google Tag Manager (HelperFunction to check exclusion)

HelperFunctions.cshtml

@functions {
    public static string TrackThisPage()
    {
        if (Request.QueryString["ignoreGTM"] != null && Request.QueryString["ignoreGTM"] == "false")
        {
            return "true";
        }
        else if ((Request.Cookies["ignorePageViews"] != null && Request.Cookies["ignorePageViews"].Value == "true") ||
            (Request.QueryString["ignoreGTM"] != null && Request.QueryString["ignoreGTM"] == "true") ||
            Request.Path.EndsWith("ignore", StringComparison.InvariantCultureIgnoreCase) ||
            Request.Url.Host.Contains(".local"))
        {
            return "false";
        }

        return "true";
    }
}