You can't "upgrade" to TurboTax Business (different from Home & Business). To file a 1041 Trust return, TurboTax Business has to be purchased in full as a completely separate product. It's only available for the Windows operating system. It won't work on a MAC, and it's not available as an online product.
You can purchase the CD at https://turbotax.intuit.com/small-business-taxes/ After you pay for it, you can download the CD installation file and install it immediately without having to wait for the CD to arrive.