Decide if you want to enter your own calculated amount or let HR.my calculate it based on a percentage of employee's gross income. If you would like to enter your own calculated amount, then set Amount Type to "Amount", otherwise set Amount Type to "% Gross Income".
You may leave both Employer Portion and Employee Portion as zero or enter specific values. Either way, you may always assign different values again when setting up an employee's salary profile or when you are ready to process the payroll.