You might get an additional refund if you had unemployment income in 2020. You do not have to do anything, but you might have to wait a few more months. The IRS expects to send the refunds out over the course of the summer and there is no way to track it so all you can do is wait.
You will not get an amended tax return form, just the additional refund and a letter explaining it.
For more details see the following IRS announcements and FAQ.
IRS to recalculate taxes on unemployment benefits; refunds to start in May
IRS begins correcting tax returns for unemployment compensation income exclusion
IRS sending more than 2.8 million refunds to those who already paid taxes on 2020 unemployment compe...
2020 Unemployment Compensation Exclusion FAQs
