As stated in the readme: If you use the full version of the mod using the mod framework, there is an optional flags folder in the download. You can copy one flag file from that folder into the framework folder. For example, copy flags.sa-objective.json if you want the sa objective only. The file needs to end up in the same folder as flags.json that you downloaded with the framework. After copying, you must update your mods with the framework again.
Alternatively, you can edit flags.json in the framework folder without using any optional files. If you don't understand what I mean by that, use the optional files.
Either way, this does NOT enable the normal sa indicator, it adds a new objective displayed as long as you have sa status instead.