You can use TurboTax to e-file a 2019 tax return at any time up through October 15, 2019.
If you have already filed your 2019 tax return you would need to amend the return that you have filed to add the W-2.
See this TurvrboTax support FAQ for amending a 2019 tax return - https://ttlc.intuit.com/community/tax-topics/help/how-do-i-amend-a-2019-return-in-turbotax/01/123845...
