The employee's payslip that available to be downloaded is only the payslip that already generated.
To generate the payslip, you can follow the guide here.
1. Go to Payment menu
2. Go to Payment Summary tab
3. Select Month of the payslip
4. Tick the payslip that you want to download
You can also tick the checkbox in the column header to select all.
5. Click Download Summaries
After that, you can save the downloaded payslip file in your device.