Odin cannot add Synaptic Package Manager or Steam

Question

It is not available via the AppCenter, and installing it manually results in an app that asks for authentication and then exits.

I wanted to use Synaptic to install Steam, as I had under Elementary OS 5.

Answer 1

In terminal,

sudo apt update
sudo apt install synaptic 

Answer 2

Elementary OS is moving towards flatpak packages. It is highly recommended you install the flatpak version of steam.

Just open that link and press Install. Then it will open a Sideload screen that will let you install Steam on your system.