- Download the Steam Client here.
- Log in to your Steam account and click on Games > Activate a Product on Steam.
- Click Next when you see the Product Activation pop-up.
- Please Agree the Steam Subscriber Terms.
- In the ‘Product Code’ section, enter your unique code that’s displayed on the ‘Order’ page of your CDKeys account or on the link of your confirmation email if you had purchased as a guest and follow the prompts to activate.
- Your game is now viewable in the ‘Library’ tab and is available to download/install.
You can find additional support for the Steam client here: https://help.steampowered.com/en/wizard/HelpWithSteam