To create and file a Form 1065 return, you need TurboTax Business.  This version is only available as a CD/downloaded product for Windows computers.

Use this link for more information or to purchase it:  TurboTax Business

I recently purchased Turbo Tax Deluxe with State for 2020 at Office Depot.  This is what I have used for years.  Turns out that I have to do a 1065 as well this year and was not aware that it was not included in the Deluxe version.  Is there a way that I can do the 1065 form and related forms?  I have read the post on the message board and it indicates that I will need the Business Version of TurboTax.  Since I have already purchased and begun using Deluxe is there any way to discount the purchase of Business to get what additionally I now need?

No discounts from TT ... you may buy the BUSINESS version from a reliable reseller : 

This link Where can I obtain authentic TurboTax software? has a list of authorized TurboTax resellers.

No.  You need Turbo Tax Business in addition to a personal version like Deluxe.  So you will need both.

The small business program (TT Business) is for 1120 Corporation, 1120S Corp, 1065 Partnership or 1041 Estate/Trust returns and will not do your personal 1040 return.   It  is a separate program from the Desktop Home & Business program or the Online Self Employed version.

Turbo Tax Business  is not available to do online or on a Mac.  You can buy the Window's version here.  And you can have both TT Business and TT Home & Business (or any personal version) installed on  your computer at the same time.

https://turbotax.intuit.com/small-business-taxes

Desktop Windows System Requirements

https://ttlc.intuit.com/community/system-requirements/help/minimum-system-requirements-for-turbotax-...