It can be anything! An apex, subdomain, or even a URL.

Results foreu.dev.test.arexdata.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2022-09-09T07:51:28.911	2022-09-09T06:51:28	2022-12-08T06:51:27	elasticsearch.eu.dev.test.arexdata.com	elasticsearch.eu.dev.test.arexdata.com	C=US, O=Let's Encrypt, CN=R3
2022-09-09T07:51:28.565	2022-09-09T06:51:28	2022-12-08T06:51:27	elasticsearch.eu.dev.test.arexdata.com	elasticsearch.eu.dev.test.arexdata.com	C=US, O=Let's Encrypt, CN=R3
2022-09-09T07:51:28.074	2022-09-09T06:51:27	2022-12-08T06:51:26	kibana.eu.dev.test.arexdata.com	kibana.eu.dev.test.arexdata.com	C=US, O=Let's Encrypt, CN=R3
2022-09-09T07:51:27.868	2022-09-09T06:51:27	2022-12-08T06:51:26	kibana.eu.dev.test.arexdata.com	kibana.eu.dev.test.arexdata.com	C=US, O=Let's Encrypt, CN=R3