...
stepover-pdf-service-windows-x32-5.3.0_b221.exe
on Windows, 32-bit, x86,
stepover-pdf-service-unix-5.3.0.sh
on Linux, x64,
stepover-pdf-service-macos-5.3.0.dmg
on MacOS, x64,
stepover-pdf-service-macos-arm-5.3.0.dmg
on MacOS, arm64.
The MacOS installers may not be notarized.
See the Apple docs on how to run them nevertheless.