If you bought a new Office product key card, or you received a product key when you bought Office through an online store, go to https://setup.office.com/ and follow the on-screen prompts. Redeeming your product key is a one-time process that adds your new Office product to your Microsoft account. When you're done, you'll use your Microsoft account, not your product key, to install and activate Office.
Sign-in your Microsoft Account:
Enter your Product key:
Install your Office: