Hi @Craig E Cooper ,
As you said that "The installed went well including the license key", I am assuming that you are going to activate Office whose license type is volume licensed (not retail). Generally, you only need to enter the license key in any Office product one time and all office products will be activated. So, please run
cscript ospp.vbs /dstatus at the command prompt and check if the license channel is reflected as VOLUME. See detailed steps in this article: How to determine the license type of your Microsoft Office product. You have to make sure you have installed the correct version of Office 2016 firstly. It's welcomed to share the screenshot of the command result here and we are glad to help you check and provide further support.
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