My OS at this time is an arch based distro (Garuda). The Epic Games Store is not easily available for me. The alternative solution to download Unreal Marketplace assets is simple though. You still to purchase assets (free or paid) via your web browser to associate them with your account first.
Once that is done, install Legendary. It’s an open source Epic Games Launcher alternative, cli-based at the time of writing.
Once you’ve installed it using your package manager of choice, you can authenticate with the command legendary auth
Once you’re authenticated, you can list your available products with legendary list. By default, it only shows games, but if you pass in the --include-ue option, you will also be shown content relating to Unreal Engine and Unreal Marketplace that are associated with your account.
If the list is too large, you can pipe the result to grep to filter it down.
The final step is to install this content. You can use the command legendary install <App name> for that.
In my case, the content was installed in the /home/Games directory.