I understand that AVMA activation only works with a Datacenter edition host machine. However, the Standard edition is supposed to allow 2 VM installs of Standard as well, but how should those VMs be activated without AVMA?
nslookup -type=srv _vlmcs._tcp to make sure there's a DNS record for your KMS host server.
slmgr.vbs /ipk WC2BQ-8NRM3-FDDYY-2BFGV-KHKQY to activate.
I found the KMS Client Setup Key here: https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-R2-and-2012/jj612867(v=ws.11)