This indicator is meant to be a tray icon switcher for all the other desktops besides the Gnome desktop which is already supported by the fabolous system76 guys.
Since this is a system76 powr indicator you need to either use a pop! os or installed system76-power by yourself, somehow … Besides that we need python and a bit of gtk support.
- System76-power you have to install by yourself
The tool itself needs a firm:
sudo apt install python3sudo bash ./setup.sh