assuming you're on PC?

log in to your SQEX acct on the Mogstation and apply the code from your copy of ARR into your account (this would be the Windows/PC version). That should unlock the game for you and add 30 days of game time to your account. Then you can set up either a recurring subscription and pay via credit card or crysta, or if you choose to pay via time cards you can buy those and enter the codes from those to add game time to your account.