使用HttpClient或其他网络请求库来获取外部网站信息。例如：

public static async Task Run(HttpRequest req, ILogger log)
{
    string url = "https://example.com";
    
    using (var client = new HttpClient())
    {
        var response = await client.GetAsync(url);
 
        if (response.IsSuccessStatusCode)
        {
            var content = await response.Content.ReadAsStringAsync();
            return new OkObjectResult(content);
        }
        else
        {
            log.LogError($"Failed to get {url}. Status code: {response.StatusCode}");
            return new BadRequestObjectResult("Failed to get external site information");
        }
    }
}

在此示例中，我们使用HttpClient来获取外部网站信息，并根据返回的响应来进行不同的操作。如果响应成功，则读取响应内容并以OkObjectResult返回；否则，将日志记录为错误并以BadRequestObjectResult返回错误消息。