If you do not want to have the 2020 desktop software automatically sent to you, then you will have to cancel your Advantage subscription. You can always start the subscription again at any time you wish to do so.
See this TurboTax support FAQ for canceling the Advantage subscription - https://ttlc.intuit.com/community/downgrading/help/how-do-i-cancel-my-turbotax-advantage-subscriptio...
