Those who played the Call of Duty: Black Ops 4 Multiplayer Beta back in August will get a nice little message as they load up into Call of Duty: Black Ops 4 at launch for the very first time.
The game informs you that, for playing in the beta, you are awarded an additional Beta Calling Card to use in the game. Alongside this, if you reached level 34 or higher during the MP Beta, you are awarded 1 Permanent Unlock Token to unlock any items in MP.
The Unlock Token should automatically show up in your profile, as long as you see the message shown above in game as you load up. The Calling Card is available to equip under Menu -> Identity -> Calling Card in MP.