The Qualified Business Income (QBI) deduction is shown on Line 13 - Qualified business income deduction from Form 8995 or Form 8995-A of the 2023 Form 1040. The QBI deduction was on line 10 of Form 1040 for 2019 but has been on line 13 since 2020.
Your QBI deduction should have been added to your standard or itemized deduction from line 12 to get your total deductions on line 14. That amount would have been deducted from your adjusted gross income on line 11 to get your taxable income on line 15.