Replace bobswinkels with your username and place files at correct locations:
/Users/bobswinkels/bin/backup.sh/Library/LaunchDaemons/com.restic-backup.plist
Launch deamon using:
sudo launchctl load /Library/LaunchDaemons/com.restic-backup.plist
Alternatively the script can also be run using a cron job:
0 */6 * * * /Users/bobswinkels/bin/backup.sh >> /var/log/restic-backup.log 2>&1