Company-wide ones go in Payroll, Allowances & deductions: choose Deduction or Allowance, the Name, how it is Worked out (% of gross pay or a fixed amount), an optional Most per pay, whether it is taken before tax or taxed, and which employment types it applies to, then press Add.
For one driver, use This driver's regular allowances and deductions on their page. In the US, Canada and India, Add standard (your country) deductions adds Social Security and Medicare, CPP and EI, or Employee PF in one go.