How do I get Free Download Manager to work on Pop!_OS?

You might want to give us more details about how you installed it. There are different ways to go about it, like using an app image or compiling from source, and diagnosing the issue will depend on that. Also, remember that the name "Free Download Manager" is super generic and can sometimes lead to downloading the wrong software.

First off, make sure you're using the official repositories for Pop!_OS instead of downloading directly from the website. It's a safer approach. Also, I'm curious—why do you want to use Free Download Manager? It seems a bit outdated considering there are many other options available nowadays.