try
{
  // Bucket name in the format of bucketname-APPID. You can get APPID by referring to https://console.tencentcloud.com/developer.
  string bucket = "examplebucket-1250000000";
  string key = "exampleobject"; // Object key
  RestoreObjectRequest request = new RestoreObjectRequest(bucket, key);
  // Restoration time
  request.SetExpireDays(3);
  request.SetTier(COSXML.Model.Tag.RestoreConfigure.Tier.Bulk);

  // Execute the request
  RestoreObjectResult result = cosXml.RestoreObject(request);
  // Request succeeded
  Console.WriteLine(result.GetResultInfo());
}
catch (COSXML.CosException.CosClientException clientEx)
{
  // Request failed
  Console.WriteLine("CosClientException: " + clientEx);
}
catch (COSXML.CosException.CosServerException serverEx)
{
  // Request failed
  Console.WriteLine("CosServerException: " + serverEx.GetInfo());
}