I also tried this solution from altjx in this thread which did not work
[Unit]
Description=Greenbone Security Assistant (gsad)
Documentation=man:gsad(8) https://www.greenbone.net
After=network.target gvmd.service
Wants=gvmd.service
[Service]
Type=forking
User=_gvm
Group=_gvm
ExecStart=/usr/sbin/gsad --listen=127.0.0.1 --port=9392
Restart=always
TimeoutStopSec=10
[Install]
WantedBy=multi-user.target
Alias=gsad.service