How to Redeem a Steam Gift Card

Go to this website: Visit the Steam website at www.steampowered.com or open the Steam app.
Log in to your account: Enter your username and password to log in to your Steam account.
Navigate to the Wallet section: Click on your account name in the upper right corner and select “Account details” from the drop-down menu. Then click on “Add funds to your Steam Wallet.”
Select Redeem a Steam Gift Card or Wallet Code: Click on “Redeem a Steam Gift Card or Wallet Code.”
Enter your code: Enter the code from your Steam Wallet card and click “Continue.” The funds will be added to your Steam Wallet balance.