Per the Instructions for Schedule K-1 (1065), page 17:
Codes Z through AD. Qualified business income deduction. Generally, you are allowed a deduction up to 20% of your net qualified business income plus 20% of qualified REIT dividends and qualified PTP income from your partnership. The partnership will provide the information needed to figure your deduction. Once you have this information, you will use one of two worksheets to help you figure your deduction for qualified business income.
Use Qualified Business Income Deduction - Simplified Worksheet, included in the Instructions for Form 1040, if:
Code Z. Section 199A qualified business income. Use the appropriate worksheet to report your portion of qualified business income.
To enter the Qualified business income (QBI) information from Schedule K-1 in TaxAct: