How / Where is Application.installmode set?

I’m on Unity 2021.3.16f1 and looking to execute certain part of the code only when the application is run on user’s machine, and not when I’m testing out via Editor or Player mode.

I see there’s Application.isEditor boolean that could be used but it still will run the undesired code when I’m running the binary.

I then came across Application.installmode which looks promising on the face of it but there is trivial documentation on how to use it properly.

You can use compiler directives to execute code only on specific platforms, like, e.g.

using UnityEngine;
#if UNITY_EDITOR
using UnityEditor;
#endif

...

    public void Exit()
    {
#if UNITY_EDITOR
        EditorApplication.ExitPlaymode();
#else
        Application.Quit();
#endif
    }