How to use an Xbox One download code from Smyths Toy Store
If you buy a DLC from Smyths Toy Store you'll receive an email with the download code.
For Xbox One, turn on the console and navigate to Store on your dashboard.
Look for a small button that says "Use Code".
Type in the code from the email (It's easier if you pair your phone to the Xbox One and type it in using the phone keyboard).
Press A and then the purchase will be downloaded to your Xbox One.
If you have pre-ordered a game, such as Battlefield 1, it may be a bit confusing.
Usually the code sent to you by email is for an extra downloadable content pack. They will still send you the game in the post.
You can type in the code but it won't download until the game is installed.