A 2019 W-2 cannot be entered on a 2020 tax return.
To enter the 2019 W-2 you will have to amend the 2019 tax return that you filed.
See this TurboTax support FAQ for amending a 2019 tax return originally completed and filed using TurboTax - https://ttlc.intuit.com/community/tax-topics/help/how-do-i-amend-a-2019-return-in-turbotax/01/123845...
