finding the BETA

[Gadger]

Im not 100% sure if I'm just being really stupid, or the beta isn't keen on my iMac or something, but I cant seem to find where or how to download it at all... It's actually really annoying me that everyone else seems to be able to find it.
I have the BETA code from Game and just cant find where to enter it.

I have gone to Steam then in the Store > Games and cant find the relevant bit...

Please help somone

 

[LiamMagwood]

If it is a code, go onto steam and at the top there is row of tabs, click on games and then click on 'Activate a product on Steam'