wagnerjer

Windows client:
slmgr /act » Will activate the license against KMS
slmgr /rearm » will reinitialize CMID but will also remove current count on KMS (useful for VDI to count all activation)

Windows server:
slmgr /dli » Display the current license information with activation status and partial product key.
slmgr /dlv » Display additional license information. Similar to /dli but more detailed.
slmgr /dlv {product ID} » Display additional license information about specific product.

Office 2019 : 70512334-47B4-44DB-A233-BE5EA33B914C\\
Office 2021 : 7F3B983-7C53-4D45-ABC6-BCD91E2DD90A\\

To allow server to activate Office licenses you must install Office license package that you get from Microsoft website
Ex: https://www.microsoft.com/en-us/download/details.aspx?id=57342

Check that DNS record is correct:

nslookup -type=srv _vlms._tcp
Server:  fqdn
Address:  XX.XX.XX.XX

*** FQDN can't find _vlms._tcp: Non-existent domain

Test connection to server

Test-NetConnection your-kms-server-name –Port 1688

Office client:
Navigate in Office folder Ex: C:\Program Files (x86)\Microsoft Office\Office16
Activate product:

cscript ospp.vbs /act

Check license status

cscript ospp.vbs /dstatusall