How I convert it to SQL Server please
SELECT 
    inbox.ItemId,
    item.NAME,
    inbox.Expiratory,
    t = SUM(inbox.TotalNumber)
FROM dbo.Item 
INNER JOIN dbo.inbox
ON Item.ItemId = inbox.ItemId
WHERE NOT EXISTS
(
  SELECT 1 FROM dbo.Outbox
    WHERE Item = inbox.Item
    AND Expiratory = inbox.Expiratory
)
GROUP BY inbox.ItemId, item.NAME, inbox.Expiratory;