Then the question would be why systemd isn’t doing as well. Did you test any setup directions?
You can practice on system systemd, i.e. systemctl status duplicati and journalctl -f.
If those look reasonable, then the setup directions suggest you can add --user to see that one.
The status command will also show where your unit file lives, so you can check if you edited it.
I doubt it. There’s nothing magic about 8200 that lets you in without a password if you’ve set one.
I’m not sure what the unit file looked like before you started edits. The one I know pulls options in.
# cat /lib/systemd/system/duplicati.service
[Unit]
Description=Duplicati web-server
After=network.target
[Service]
Nice=19
IOSchedulingClass=idle
EnvironmentFile=-/etc/default/duplicati
ExecStart=/usr/bin/duplicati-server $DAEMON_OPTS
Restart=always
[Install]
WantedBy=multi-user.target
/usr/bin/duplicati-server (look at the script) runs Server. /usr/bin/duplicati runs TrayIcon.
If you prefer, you can put the password there or obtain it from any more secured source that you like.
The GUI password is there to protect the GUI, not protect against local users with direct shell access.
I think you should solve systemd, but it’s your choice. Systemd experts out there, feel free to help.