You do not report a form 1099-K on your return. However, all of your income (sales) is always reportable as your business income (box 1a), which you can enter under general/additional income for your self-employed business. The form 1099-K is a requirement for the payment processor to the IRS and you receive a copy for your records.
Their de minimis filing requirement is if payments to someone exceed 200 transactions, or $20,000. However, they can choose to file for people below the requirement as well, but this has no impact on your return. You should report all your income, regardless.
Learn more here: https://www.irs.gov/payments/general-faqs-on-new-payment-card-reporting-requirements