I agree, it's taxable, sorry.
It's "miscellaneous" or "other" income, similar to hobby income or gambling prizes. It is not compensation from working, and you are not a business, you don't use schedule C and you don't pay self-employment tax. You can't deduct any expenses you might have had.
Your "other income" is reported in Turbotax and on your tax form and is subject to the same regular income taxes as wages. It's included on your regular tax return (form 1040) at the end of the year, not a separate form.
However, because you did not have withholding, you will need to make an estimated tax payment to the IRS and your state government. If you owe a large tax amount when you file your return, you can be assessed an underpayment penalty, even if you pay in full when you file. Depending on your other income and what state you live in, I suggest a 5% payment to your state and a 20% payment to the IRS. That may not be enough to cover all the taxes, so you may still owe at the end of the year, but it will be enough to prevent paying a penalty. If you want to intentionally overpay your estimate, and get the extra back as a refund, then pay 25% to the IRS and 10% to your state.
Estimated tax payments to the IRS can be made electronically at www.irs.gov/payments. Be sure to select "2022 estimated taxes" as the reason. Your state should have a similar web site for payments.
