The general rule is one is required to report all income regardless of source.
Extending that general rule to any income that is reported by another party to the IRS definitely should be reported on your tax return.
In the case of Form 1099-K, you report the income under Wages and Income, Other Common Income, Tax refunds, 1099-NEC, 1099-MISC, 1099-K.
If you are self-employed and the 1099-K is reported payments from a third party payment handler like PayPal, or a credit card company, you can enter your business expenses through self-employment expenses on Schedule C.
If you are not self-employed and these payments were incidental for sale of personal items you can enter a reversing entry by going to Wages and Income, Less Common Income, Other Miscellaneous Income, Other Taxable Income.
https://ttlc.intuit.com/community/taxes/discussion/re-i-received-a-1099k-of-1-000-sold-personal-item...
