

You can absolutely use your external IP rather than a domain, your ISP likely keeps your IP the same for long stretches of time. Mine only ever really changes during long power outages.
You can get around that the IP issue by broadcasting your ip from your local machine to a known service, there are some free ones but they aren’t the most stable things in the world if it’s critical. Google Dynamic DNS


Tongue depressor is a common example of this use case.