The status "Handled" means that you have archived the invoice, but no payment request has been sent to the bank. If you have chosen to mark an invoice as "Handled," you must personally ensure that the invoice is paid by other means.
If you wish to pay an invoice that you have marked as "Handled," you can change the status so that it becomes payable again. Open the invoice, click on the three dots in the top-right corner and select "Mark as unhandled." You will then be able to pay it directly in Kivra.