systemd service

(recommended method):

Create a file inside the folder /etc/systemd/system named passerverd.service
with a content like this

[Unit]
Description=GiD password server: floating password for GiD and problemtypes
Requires=network.target
After=systemd-user-sessions.service
StartLimitIntervalSec=0

[Service]
Type=simple
ExecStart=/usr/local/passerver/passerverd -port 7073
Restart=always
RestartSec=1

[Install]
WantedBy=multi-user.target

And to enable it during startup run once

sudo systemctl enable passerverd.service

then the service can be started/stopped with

sudo systemctl start passerverd.service
sudo systemctl stop passerverd.service