BF:BC2 CD-retail key on steam

[TheInari]

I purchased BF:BC 2 back in 2016 and now I am trying to activate the game, however it will not show me my retail CD-Key on steam, only for the Vietnam and Specact Kit DLCs. 

I am aware the servers are either shut down or shutting down, but want to at least enjoy a game from my childhood if possible.