This would be a simple endpoint in front of any auth that responds with a simple ok and 200 status code used for infrastructure monitoring.
Back in 2021, it sounds like no: Web API to monitor Ignition server health?
The suggestion in that post is to use the WebDev module, but we don't use that and it costs $2249.08, i.e. prohibitive for such a simple feature.
More recently, I saw Ignition has a "Ignition + Docker" webinar that mentions this kind of monitoring, but can't find anything in the docs on this.
I also did some digging because Ignition's docker image has a healthcheck configured, but it's not hitting an endpoint, just running a linux utility: Docker