Windows Server 2019 standar and virtual machines

You can use the Server 2019 Standard License on one host and two virtual machines, but only if the host license is used for a Hyper-V Host Server which hosts the virtual machines.

Aside from disaster recovery scenarios you are also not allowed to move this VMs to a different host. And as the physical host where you use the license has to be the one that runs the 2 vms, you should not run anything else on this host aside from virtualization.

It's not 3 licenses, it's either 1 full physical server license or 2 virtual licenses + 1 physical Hyper-V Host for the virtual machines.

If you host 4 virtual machines on the same host, you need 2 server standard licenses, both assigned to the same physical host (you only need to use one of the 2 keys to activate the host of course), which means you can't use the license on any other physical host! JosueGonzalezC