Log in to www.microsoft.com/msppdd Using the Microsoft ID for your MPN account.
Click on Microsoft Online Services for Online services like Office 365, Dynamics 365 etc..
The software available for download and usage is displayed:
Identify the software key by clicking on View link.
Click on the Gold Core Benefits or the Silver benefits to view the key.
Click on this link to use the code.
You will see this login and warning:
Follow the instructions.. and sign in with your work account clicking on the sign in button on the top right.
Click on Add Another Product key if you have multiple keys you want to redeem.