That depends on which day of the week you look at the IRS website.

https://www.irs.gov/forms-pubs/new-exclusion-of-up-to-10200-of-unemployment-compensation

On Tuesday it said "If you have already filed your 2020 Form 1040 or 1040-SR, there is no need to file an amended return (Form 1040-X) to figure the amount of unemployment compensation to exclude. The IRS will refigure your taxes using the excluded unemployment compensation amount and adjust your account accordingly. The IRS will send any refund amount directly to you."

But then on Wednesday it said "If you have already filed your 2020 Form 1040 or 1040-SR, you should not file an amended return at this time. The IRS will issue additional guidance as soon as possible.".

I haven't looked today.