Sharepoint - Attach file in CustomList Item using Sharepoint.Client object

I already solve my problem below is my code:

List docs = web.Lists.GetByTitle("CustomList");
ListItem item = docs.GetItemById(ID);

var attInfo = new AttachmentCreationInformation();
attInfo.FileName = mFile.Name;
attInfo.ContentStream = new MemoryStream(System.IO.File.ReadAllBytes("streamFile"));

Attachment att = item.AttachmentFiles.Add(attInfo); //Add to File

context.Load(att);
context.ExecuteQuery();
Console.WriteLine("done");

Hope this helps other developers too. Regards!