If you get the message "TurboTax cannot be opened because Apple cannot check it for malicious software" then that is caused by the Apple "Gatekeeper" introduced with OS X 10.15 (Catalina).
That has nothing to do with TurboTax and will happen for any application not purchased from the Apple Store.
See this Apple article on this: https://support.apple.com/en-us/HT202491
And this TurboTax help article: https://ttlc.intuit.com/community/troubleshooting/help/turbotax-for-mac-won-t-open-when-installed/00...
