To activate a Steam gift, you received from a friend, you need to click on the notification. Make sure you accept it or it will be refunded to the sender. 1. Launch Steam. 2. Check your notifications. 3. Click on the corresponding notification. 4. Select “Accept Gift.” 5. The game will be added to your Steam library immediately. 6. Go to your library and then locate the game. 7. Install it. 8. Once the installation process is complete, you can play the game.