The reward is unlocked on your account, there is no email with a code for that emblem. If you claimed the Triumph in game and then clicked the redeem button on the website for the reward then it will be unlocked in your emblem Collections. Be aware that the names for the emblems on the website are not the names used in the game. The Sunset reward is called Savior in game and the Eclipsed Sunset is called Eclipsed Void in game. So log out of D2, then log back in and select a character. Once your character is up, pull up your Character screen, then tab to the left to the Collections tab and select the Flair category. On the Flair screen make sure you're on Emblems then select General from the list on the left. The emblem in question will show up near the end of your General emblems. There is one glitch though, it appears for many players that the Eclipsed Sunset and Sunset emblems are reversed when they claim their rewards. So when you claim Sunset you likely got Eclipsed Void in your Collections instead of Savior.