if some clients paid me in cash, how do i enter that amount?

[marcwhite]

where do i enter revenue that was received as a cash payment, not paid by credit card, not paid by debit card, not paid by electronic payment?

[VolvoGirl]

You can just enter it as Other self employment income or as Cash or General income.  You don't need to get a 1099NEC or 1099Misc or 1099K.  Even if you did you can enter all your income as Cash.  Only the total goes to schedule C.

How to enter income from Self Employment

https://ttlc.intuit.com/community/self-employed/help/how-do-i-report-income-from-self-employment/00/...