I’m currently doing my 2023 taxes and got a W-2C from 2020. How do I input that?

[VolvoGirl]

You might need to Amend your 2020 return.  What was changed on it?  

How to Amend a prior year
https://ttlc.intuit.com/community/amending/help/how-to-amend-change-or-correct-a-return-you-already-...

[DoninGA]

You cannot enter a 2020 W-2C on the 2023 tax return.

If the gross income or taxes withheld changed on the 2020 W-2C versus what was entered on the original 2020 W-2 you will need to amend the 2020 tax return.

See this TurboTax support FAQ for amending a tax return - https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-return/amend-change-correct-return-a...