First things first, log into your Activision account and go to the Account Linking tab. Here, scroll all the way down and find the option that says 'link your Twitch account.' After you click on ...

After you have set up an account, go over to the official Little Caesars x Call of Duty promo site. There, you'll see the 'Unlock Rewards' button, which will link you to your Activision account ...