Configure Syncthing as a system service
Create the user who should run the service, or choose an existing one.
Copy the system syncthing@.service file into the load path of the system instance. Replace <user> with the name of the user who'll own the service.
sudo cp /usr/lib/systemd/system/syncthing@.service /etc/systemd/system/syncthing@<user>.service
(NOTE: The above paths make sense in Ubuntu, but they may not be correct in other Linux distros.)
<user> with the actual Syncthing user after the @:systemctl enable syncthing@<user>.service
systemctl start syncthing@<user>.service