You can also use Healthchecks[0] or Uptime-Kuma[1] both of which are open source and self-hostable! I've been using both for a while and they're great. Healtchecks has first class integration in borgmatic[3], and is in my opinion the better choice for cron jobs. Uptime-Kuma has a really nice interface and also supports checking hosts/services via ping or http request. It also supports "push" requests a la healthcheck…
`curl --header "X-Api-Key: your-api-key" " rel="nofollow">https://healthchecks.io/api/v1/checks/` does not contain the passed request body.