If you see this window instead you need to activate your key by using the automated phone system. Go back and to the next step.
Choose the phone activation option and click Next.
Now choose your country and call the provided number and follow the steps to point where you enter the installation ID and receive the confirmation ID which you put into boxes A-H.
If you see a message about Phone Activation being no longer supported disregard it, this message is displayed to everyone who is not a subscriber of Office 365. Phone number can be found here on official MS website.
After typing in the Confirmation ID from MS hit next, product key will be verified and that’s it. Office is successfully activated and ready to use.