Bring down the sky CD Key

Hello

I have downloaded bring down the sky DLC. But i were never provided with a CD key. I dod not get an e-mail or anything with this info. I do have Mass Effect 1 and can provide the CD-Key from that game if needed.

On the BioWare site it is stated that i must register Mass Effect 1 game to get a free CD-key to bring down the sky. The link there only brings up the main page.

I have also tryed to go to my games to activate the game from there but only Mass Effect 2 and 3 are on that list.

I have tryed to use the Bring down the Sky DLC redemption but installer tells me this is an invalid CD-key

How should i proceed to get this CD-Key?