1099s may list income that is genuinely not taxable. An example would be someone whose roommates Zelle him their share of the rent each month, then he pays the full rent. This is not taxable income, even though Zelle might report it on a 1099-K.
So, how do you exclude this from taxable income? First, enter all 1099s on your return. Then, total up (and document) what is not taxable. Enter that number as a minus amount on Schedule 1 Line 24 z Other adjustments. You’re done! This minus number automatically flows through to Form 1040 Line 10 Adjustments to income, and gets subtracted from taxable income.
Document on the return why the income is being excluded, then save all records in case the IRS challenges it.