Your liabilities are based on the taxes calculated on your employee's paychecks. You'll have to select the garnishment as an additional deduction of your employee's information. This way, it'll be included in the tax calculation every time you create a paycheck.
Go to Employees.
Click Employee Center.
Find and open your employee's profile.
Select Payroll info.
Under ADDITION,DEDUCTIONS AND COMPANY CONTRIBUTIONS, select the garnishment.