When you first open the game on the Xbox One or PS4, you will be prompted to link your Xbox or PSN Account to an Arc account.
If you select Open in Browser, you will be redirected to the Arc website, where you will be asked to sign in using an existing Arc account, or to create a new Arc account in our system. Whichever method you use, after you have signed in with an account, you will be asked to enter the code shown in the prompt on your screen, which is unique to your Xbox or PSN Account. Don't worry, if you do not remember the code off-hand, the code will automatically be filled in for you, with the option to change it if desired. Once you have entered a code, you will be all set and your account will be linked!
You can also skip the initial linking process and choose to link later by selecting Link Account under Options on the Main Menu.