Install Command Line Options - ALLUSERS (per-machine installation)

Hello,
I have an installer that supports silent installation (/S). But by default it installs for the current user only.
How can I force a per machine installation? Meaning shortcuts for all users.

I tried with a setupvars.ini-file, that works for installing in a different folder for example. But I cannot find the Session Variable to force an ALLUSERS installation.

Is that possible with the .ini file please?

Thanks.