Missing pt-device-manager

I am running Raspbian-Jesse. I tried to install pt-battery and when I tried to install pt-device-manager, I received a failure that ended with

“Package ‘pt-device-manager’ has no installation candidate.”

Any hope here?

Did you add the Pi-Top repos to your system?

Using pi-top Hardware with Raspberry Pi OS (formerly Raspbian)

echo “deb http://apt.pi-top.com/pi-top-os sirius main contrib non-free” | sudo tee /etc/apt/sources.list.d/pi-top.list &> /dev/null
curl https://apt.pi-top.com/pt-apt.asc | sudo apt-key add

sudo apt update
sudo apt install pt-device-manager pt-sys-oled pt-firmware-updater