thanks , and I will follow the way.
Test case :
.... passed
_client = InfluxDBClientFactory.Create(url, _user, _password.ToCharArray());
var theAPI = _client.GetWriteApi(writeOptions);
theAPI.EventHandler += ShowWriteEvent;
... when I try to write data
theAPI.WritePoint(_point, _bucket, _org);
.... I got error event (unauthorized access)