You can register an advance payment if an employee has been paid an advance, and it needs to be deducted on the next payroll. The actual payout of the advance happens manually, not via Salary.
As an example, an advance of 5.000 kr. has been paid out to an employee, and if this is registered as an advance payment in Salary, the amount of 5.000 kr will be deducted on the next payslip.
So creating an advance payment in Salary is not a payout, but a way of deducting the amount on the employee's next payslip.
Go to Employees -> Select the employee -> Choose Net reduction -> Register advance/net reduction: