If you don't report the tax withheld, when the software calculates the amount due or refund, it will short you by the amount withheld. You'll wind up with a smaller refund or more likely a larger amount due.
You can get a transcript of your 2020 W-2 from the IRS.
Go to IRS.GOV
Click on GET YOUR TAX RECORD
Click on GET TRANSCRIPT ONLINE
The reason you need the transcript is FEDERAL TAX
Click on 2020 under WAGE & INCOME TRANSCRIPT
