A short script to run [rsync](https://rsync.samba.org/), and send a notification to [Gotify](https://gotify.net/) with "Success" or "Error", and the last couple of lines of the rsync log.
You can use a tool like the [Cron expression generator](https://crontab.cronhub.io/) to calculate your cron timings, should you wish to automate the backups.