Problem
You want to install the Desktop version of Payroll4 on a Mac.
Cause
A Mac is not compatible with Microsoft Windows. Software developed for Windows does not work directly on a Mac.
There is no special "Mac version" of the software available.
Solution
Install Microsoft Windows on the Mac using an emulator like Boot Camp or Parallels and you will be able to run all software designed for Windows.
See also:
https://windowsreport.com/pc-emulation-software/
Solution
Use the online version of Payroll4
https://www.itman-nv.com/online