On Alexa Device
First, download the Alexa app on your phone and follow the screenshots ( * see below) to enable Be Real.
Then start by saying, “Alexa, Be Real.”
On Google Device
Start by saying, "Hey Google, Talk to Be Real."
When either device says "Ready to play?"
Just say, "Redeem code" and wait for the device to ask for the code. Then, say your code!
After saying the code listed in your gift box, your account will have full access to Holiday Edition premium content!
Note: you can also say, "Redeem code" at any time during the game to activate premium mode.
Check out these screenshots for enabling the Be Real Skill on Alexa: