Cd-Key in Battlefield Bad Company 2 Ultimate Edition

Hi. Recently I bought Battlefield Bad Company 2 Ultimate Edition.  Then I bought Vietnam in the PSN store for 14.99.  Then I go in to the Bad Company page to refresh my veteran status.  I click in the Vietnam avatar, and ask me to introduce the cd-key.  I can't add Battlefield Vietnam because Bad Company 2 dont have cd-key. Only Proof of Purchase.  I want to add Vietnam to my veteran status. Help me, please. Thanks