If you had unemployment,
If you have filed. The IRS will recalculate your return for the new unemployment exemption for you. There is no need for taxpayers to file an amended return unless the calculations make the taxpayer newly eligible for additional federal credits and deductions not already included on the original tax return.
See this new article May 14, 2021
https://www.irs.gov/newsroom/irs-begins-correcting-tax-returns-for-unemployment-compensation-income-...
You may need to amend your state return,
https://ttlc.intuit.com/community/state-taxes/help/do-i-need-to-amend-my-state-return/00/2134732
By the way, you could have efiled your 2020 return by entering 0 for the 2019 AGI since it wasn't processed on time.
