Structurizr's health checks feature allows you to supplement your deployment models with HTTP-based health checks to get an "at a glance" view of the health of your software systems. See Structurizr - Health Checks for more details.
When defining your software architecture model using the client library, HTTP-based health checks can be added to the Container Instances in your deployment model. Each health check is defined by a name, an endpoint URL, a polling interval (e.g. 60 seconds), a timeout (e.g. 1000 milliseconds), and optionally one or more HTTP headers.
HttpHealthChecks.cs shows an example of how to setup the health checks, and the result can be see online at https://structurizr.com/share/39441/health.