You mean your 1040 tax return? You do not sign a W2. Sign the 1040 at the bottom of page 2.
How to mail a return from the Online version
https://ttlc.intuit.com/community/printing/help/how-do-i-print-and-mail-my-return-in-turbotax-online...
When you mail a tax return, you need to attach any documents showing tax withheld, such as your W-2’s or any 1099’s. Use a mailing service that will track it, such as UPS or certified mail so you will know the IRS received the return. Don’t forget state.
Important! Mail Federal and State in separate envelopes and mail each year in separate envelopes.
Where to mail federal paper returns
https://www.irs.gov/uac/where-to-file-paper-tax-returns-with-or-without-a-payment
But they are not processing mailed returns right now.
See this IRS page
https://www.irs.gov/newsroom/irs-operations-during-covid-19-mission-critical-functions-continue
