You will have to amend the tax return that was filed to get the unemployment compensation exclusion. But not yet since the IRS has not provided guidance on the procedure.
See this TurboTax support FAQ for information on the American Rescue Plan - https://ttlc.intuit.com/community/tax-topics/help/how-will-the-stimulus-package-impact-
Also see this IRS statement - https://www.irs.gov/newsroom/irs-statement-american-rescue-plan-act-of-2021
