See this IRS website for a CP11 notice - https://www.irs.gov/individuals/understanding-your-cp11-notice
The IRS notice you received indicates you have taxes owed for tax year 2021. If you incorrectly indicated you were eligible for a tax credit or you did not report income on your tax return then the IRS changed your tax return resulting in the taxes owed. The notice gives you the option to either agree or disagree with the IRS.
Use this TurboTax Audit Support Center website for assistance with the IRS notice you received - https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-audit/turbotax-audit-support/L6AcMoN...
