You may receive a letter (which is a form of audit) from the IRS stating that you did not report all of your income and requesting an additional tax payment.
Or, you can amend your tax return to include the income.
If you did not include it on your 2024 tax return, you will be able to amend it toward the end of February or early March when the Form 1040X has been released. If you did not include it on an earlier tax year, take a look at the following TurboTax help article for guidance about how to amend:
How do I amend my federal tax return for a prior year?