TLS Certificate Check behind HAProxy

Hi,

i'm running Elasticsearch stack 7.16 to monitor some linux servers and check tls certificates.
Now i have an HAProxy with several backend servers hosting websites. I have configures ssl certificates at haproxy and at the backend servers.

I would like to monitor that environment.

Does anybody have an idea how to setup heartbeat configuration to monitor the certificate on haproxy AND on all backend servers?

Kindly
Thomas