If you need help recovering a lost genuine key, Microsoft support can assist with proof of purchase.
A Word 2016 activation key is a 25-character code that is required to activate Microsoft Word 2016. The activation key is used to verify that you have a genuine copy of the software and to unlock all its features. Without a valid activation key, you will not be able to use Word 2016 beyond the trial period. word 2016 activation key