i thought it should be a steam key instead of installing it?

..........................Moderator Comment...........................................

Hello zy, it is a Steam key; a Steam key for a dlc for the free to play game Forge of Gods. The dlc adds extra content that helps you along your way in game. Before your Steam account will accept the Steam key you receive, you must install the free to play game via your Steam account first, otherwise when you try to redeem the key, your Steam client detects that you don't have the base game tied to your account and won't allow the dlc to be added.

ty

Thank you for giving us this opportunity, helped me out a lot!