The last part of the install guide tells you to install a systemd startup script.
Which leads you to here:
http://wiki.freepbx.org/display/FOP/Example+systemd+startup+script+for+FreePBX
The last part of the install guide tells you to install a systemd startup script.
Which leads you to here:
http://wiki.freepbx.org/display/FOP/Example+systemd+startup+script+for+FreePBX