To uninstall in Debian:
Stop service:
sudo systemctl stop traccar.service
Uninstall service:
sudo systemctl disable traccar.service
sudo rm /etc/systemd/system/traccar.service
sudo systemctl daemon-reload
Remove traccar directory:
sudo rm -R /opt/traccar
I did this before upgrade v4.2 to 4.5
To uninstall Traccar in Ubuntu instance first your open the cmd(ctrl + alt +t).
$cd opt/traccar/bin/sudo ./traccar remove
and that's it, you removed your traccar from your system.