Did you enter an expense but you still did not receive it on your payslip?
Most probably, you added the expense after your HR manager finished the monthly payroll closing. In that case, you will receive your reimbursement on next month's payslip.
How to check your expense's payroll status
Navigate to your Expenses and click on the expense you want to check
Verify the Status. Is it approved? If not, then ask your admin to approve the expense
Verify the Payroll status
Is it reimbursable? If not, edit the expense
Is it pending? Then you added the expense too late for the last payroll closing. Your manager will then include it in the next payroll closing
Is it sent? Then you already received the reimbursement or you will receive it on your soon-to-come payslip