If you receive a gift to the same email you already have a Millie account with, the gift will automatically be credited to your wallet.
If you are not a Millie user at the time you received a gift on Millie, you'll be prompted to create an account and redeem the gift here: https://milliegiving.com/redeem
Note: if you've been invited by your company, be sure to create your account through the email invitation that was sent to your work email. Once you've done that, then go to the Redeem Gift page to redeem your gift.
Watch our how to redeem a gift video for a walkthrough: