Question

Do I really need my 2020 W-2 ?

What can I do?

Employee

To file 2021? No you don't need your 2020 W2. But you do need your 2020 AGI.

You need your 2020 AGI to efile 2021. The AGI is on 2020 1040 line 11. If you filed a Joint return you use the same AGI for each spouse.

How to find the AGI.
https://ttlc.intuit.com/community/agi/help/how-do-i-find-last-year-s-agi/01/25947

If you didn't file 2020 or filed it later in the year or mailed it, then try entering 0 for the AGI. If that doesn't work you will have to print and mail your return.

Or request a transcript from the IRS
https://www.irs.gov/individuals/get-transcript