Box 8 shows substitute payments in lieu of dividends or tax-exempt interest received by your broker on your behalf as a result of a loan of your securities. Report on the “Other income” line of Schedule 1 (Form 1040).
You can search for other reportable income (use that exact phrase) and use the Jump to other reportable income link in the search results. Or you can go through the interview screens - Here's how to enter it into TurboTax:
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