I think you are referring to the Qualified Business Income Deduction. This is a computation that is completed by TurboTax after you have entered all of your business questions. You will not enter a number for this. You can see it on line 9 of the 1040 form.
In Deluxe, you can go to search for QBI and jump to the interview questions.
If you have other questions about this, ask in the comment section below.
Here is a FAQ about this:
https://ttlc.intuit.com/replies/7019998