To add a bonus payment to employee(s) payslips, go to the Payroll utility and select an employee from the list.

On the open payslip under the 'Additions & Deductions' section, select 'Add'

Choose 'Bonus' from the list of preset Addition types:

The bonus addition type will now appear on the payslip. You can click into the € amount field and enter the bonus payment:

You can also add Bonus payments to multiple employees at the same time by using a csv file import.

To do this, go to the Payroll utility > Import > Import Additions from CSV File:

For more guidance on importing additions via CSV file, see article 'Importing Additions using CSV file' here