The Employee Retention Credit was only available for tax years 2020 and 2021. If your business was eligible for the ERC and you did not claim the credit on either your 2020 or 2021 tax returns you will have to amend those returns.
See this TurboTax support FAQ for amending a tax return - https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-return/amend-change-correct-return-a...
