Can you give us a little more information?
If you need to report a 1099-K, but then also need to subtract some of the income reported on that 1099-K (OTHER THAN EXPENSES) for example if the income is also reported on ANOTHER Form 1099, or they were personal transfers, you can make a negative entry with an explanation
Wages & Income
Less Common Income
Miscellaneous Income, 1099-A, 1099-C START or UPDATE
last option "Other reportable income" START or UPDATE
Complete the interview
Use a description that will be clear for the IRS to understand
Enter the amount as a NEGATIVE ( put a minus sign in from)
This will be on Schedule 1 to offset the excess reported on the 1099-k
Be sure you have documentation to support this subtraction and keep everything with your tax file