Stellaris: Leviathans Story Pack

To activate the key, Steam client is required:
go to the link: https://store.steampowered.com/about/ and download the client “Install Steam Now”

To activate the game key in Steam, follow these steps:

1. Install and run the Steam client and log in to your account using your account name and password (or create if you do not have one).
2. Click at the bottom left “Add game”.
3. Select “Activate product in Steam …”.
4. Follow the on-screen instructions to complete the process.
5. After successful activation of the code, go to the “Library” tab and start downloading the game.

Have a nice game!