Some general tips for Windows Licensing.
Change Eval to Standard
This changes an evaluation edition of Server 2016 to Standard edition, ready for KMS activation:
dism /online /set-edition:ServerStandard /productkey:WC2BQ-8NRM3-FDDYY-2BFGV-KHKQY /accepteula
Reboot, and then apply the KMS key
slmgr /ipk WC2BQ-8NRM3-FDDYY-2BFGV-KHKQY
Finally activate
slmgr /ato