Yes, you can use the TurboTax 2020 online editions with your personal computer's current OS.
See this TurboTax support FAQ for the online edition requirements - https://ttlc.intuit.com/community/system-requirements/help/turbotax-online-system-requirements/01/25...
The TurboTax online editions for tax year 2020 should be available in early December.
See this TurboTax support FAQ for transferring prior year tax data from your computer to the online editions - https://ttlc.intuit.com/community/entering-importing/help/how-do-i-transfer-last-year-s-return-into-...
