If you purchased a digital Steam key, follow these steps to add it to your library: : Log into your account.

Just a quick heads-up:

If you meant to write a (e.g., on Reddit, Steam forums) asking where to buy a legal key, I can help draft a safe and rule-friendly version for that too.

: Click the "+ Add a Game..." button in the bottom-left corner. Select Option : Choose "Activate a Product on Steam..." .