Add a KMS server in your pfSense firewall appliance

Tested on 23.09-RELEASE (amd64) pfSense appliance
Compiled on FreeBSD 14.0-RC4 (amd64)
Using vlmcsd-svn1113-2020-03-28-Hotbird64

All credit goes to Wind4 @ https://github.com/Wind4/vlmcsd which is a KMS Emulator in C

Nuts and bolts

1- KMS server vlmcsd is copied into the /bin directory
2- vlmcsd is then chmodded to be executable
3- A shell script called kms_start.sh is created (and chmodded) in /usr/local/etc/rc.d (to start service on reboot)

How to Install

From the pfSense web interface, Diagnostics --> Command Prompt... type
curl -L meliton.github.io/kms2pfsense.sh | sh
Then click Execute

How to Install Screenshot

Some helpful commands

From the pfSense web command prompt
netstat -an | grep 1688 to check if KMS service is running
pkill vlmcsd to kill/stop KMS service
vlmcsd -h for a list of options
vlmcsd -V for the KMS server version

NOTE: If you stop the service, you'll need to restart the firewall or SSH into the box to restart with vlmcsd command.
Typing vlmcsd from the GUI command prompt does not work.

Compile from scratch recipe

Download then install FreeBSD-14.0-RC4-amd64-bootonly.iso to a virtual machine.
Then, as root user, type the following:

cd ~
pkg install gcc git gmake
git clone --depth 1 https://github.com/Wind4/vlmcsd
cd vlmcsd
gmake
cd bin

The vlmcsd file is in the ~/vlmcsd/bin folder.