Open your Project Settings, navigate to Project > Packaging, then make sure that Use Pak File and Generate Chunks are both enabled.
DEFAULTGAME.INI
Edit your Project\Config\DefaultGame.ini file and add the following lines, making sure to customize them to fit your own needs:
The Plugin will try and download your .pak files from this location, in this example: https://eeldev.com/MyGame
[/Script/Plugins.ChunkDownloader]
+CdnBaseUrls=eeldev.com/MyGame