I cannot download my 2020 version of Turbo Tax.

Thanks for reaching out to the Apple Support Communities, jlm1945!

It sounds like you're trying to install software and seeing a message about malicious software. Check out this article to Change Security & Privacy General preferences on Mac. Specifically:

"Allow apps downloaded from

You can protect your Mac from malware by only allowing apps that come from the App Store or from identified developers.

• App Store: Select to allow only apps that have been downloaded from the App Store.
• App Store and identified developers: Select to allow apps only from the App Store, and from developers identified by Apple."

Let us know if you continue to have issues and have a wonderful day!

Find the app in the Applications folder and Control (right) - click on it. Select Open from the contextual menu and then click on the Open button in the next window. That should let you proceed.