private readonly HttpClient _httpClient;    public RemoteRequestService(HttpClient httpClient)
    {
        _httpClient = httpClient;
    }

 #region 全部退款

 // 设置目标 URL
 string url = "https://xxxx.com/api/Pay/Refund";

 // Basic Auth 用户名和密码
 string Username = "xxx";
 string Password = "xxxx@";
 // 创建 Basic Authentication 的值
 string basicAuth = Convert.ToBase64String(Encoding.UTF8.GetBytes($"{Username}:{Password}"));

 // 准备请求体
 string data = "{\"OutTradeNo\": \""+ OutTradeNo + "\"}";
 var jsonContent = new StringContent(data, Encoding.UTF8, "application/json");


 // 使用 Furion 的远程请求功能
 var authToken = Encoding.ASCII.GetBytes($"{Username}:{Password}");
 _httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", Convert.ToBase64String(authToken));
 // 发起 POST 请求
 var response = await _httpClient.PostAsync(url, jsonContent);
 // 确保请求成功
 response.EnsureSuccessStatusCode();

 var Rn = await response.Content.ReadAsStringAsync();

 #endregion