How to Set up Microsoft Office with Product Key at office.com/setup
Steps to setup Microsoft Office at microsoft365.com/setup are:
Visit www.office.com/setup and follow the on-screen instructions activation link.
Sign in to your Microsoft account or to manage your Microsoft products’ subscription, create one.
Enter your product key or code and click Next.
When your account successfully associated with the key, you’ll see the page “My Office account“.
Now, Select Install and follow the on-screen instructions.