Assuming you can add a custom URL, you can still do this through the firewall instead of an event to check the public IP. I like using my own, custom domain for this use case. I've also used and put a couple of domains up on freedns.afriad.org for others to be able to use.
That said, the only hole in my firewall/router is a port for Wireguard.
There also dozens of existing DDNS daemons out there already with far more developer, testing, and user eyeballs on them.
The firewall solution is preferred because the firewall knows when the external interface changes IP addresses, so there's no system or network overhead from having an agent repeatedly testing if the IP has changed, nor any downtime between when the IP changes and when the next check happens.