You can log back into your return and it should automatically update your return and show you the new refund. But the updated return won't be sent. The IRS will adjust it for you.
If you have unemployment you can exclude up to 10,200 for each person if your income is under $150,000. Your unemployment compensation will be on Schedule 1 line 7. The exclusion will be on Schedule 1 Line 8 as a negative number. The result flows to Form 1040 Line 8.
If you already filed and didn't get the 10,200 unemployment exclusion you do not need to amend. The IRS will be adjusting it for you. See,
https://www.irs.gov/newsroom/irs-to-recalculate-taxes-on-unemployment-benefits-refunds-to-start-in-may