Enter this value from "Refine Global Vacancy...." found in the Property drop down dialogue box. See video below.
The Default Global Vacancy is applied to the Rental Income for the entire property in a multi-family Income page and to the Rental Income plus Expense Reimbursements for the entire property in a commercial Income page. .
Only that amount which is above, or more than, Turnover Vacancy is applied. And this is reported as General Vacancy on the Projections tab and in your reports.
Left click on "QUICK HELP"