Hi marco13,
Back dating the pay slips back to 1/7/2020 you will need to create the associated pay runs for each weekly payslip. Unfortunately within the payroll system currently there is not an option to just create payslips alone without a pay run.
To create and backdate the pay period you can select New Pay Run as normal in the top right of your employee dashboard, then change the beginning date of the pay period by adjusting the ending date. Once you complete and finalise the pay run, it will then allow you to generate the pay slip.
Let me know if this helps,
-Steven
