Anywhere to use the cd key to download the game?

[Slanderous]

this post may look like spam because I just signed up. hello I recently remembered that I have a CD key for amnesia TDD but my computer doesn't have a disk drive. I already tried the key on steam, steam says that it isn't valid. I've searched the forums but pretty much no results were found, I know that CD keys aren't used anymore but I am not willing to pay 25$ (Canadian prices are high right?) for a game I already have. so if anyone knows where I can use the CD key, I would be happy. Thank You. I am NOT looking for a pirated copy. in case anyone is confused.

It might be a key for the shelf then, check it out, not sure if that works, but it might.

https://shelf.frictionalgames.com/