Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
As Dave suggested, we need some more information. Which version of Office do you have? Which operating system are you running?
P.S. To contact Microsoft support, you will have to start with the chat at https://support.microsoft.com/contactus . Often, you will get quicker assistance from your fellow users here in Q&A, though.