It is not a tax credit. It is an exclusion from income.
See this TurboTax support FAQ for information for the unemployment compensation exclusion - https://ttlc.intuit.com/community/tax-topics/help/how-do-i-claim-the-new-unemployment-benefits-in-tu...
Also see this IRS statement - https://www.irs.gov/newsroom/irs-statement-american-rescue-plan-act-of-2021
