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

Results forinfra.monitoring.dicoding.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2019-12-23T02:11:33.027	2019-12-23T01:11:32	2020-03-22T01:11:32	infra.monitoring.dicoding.com	infra.monitoring.dicoding.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-12-23T02:11:32.89	2019-12-23T01:11:32	2020-03-22T01:11:32	infra.monitoring.dicoding.com	infra.monitoring.dicoding.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-12-23T01:55:30.135	2019-12-23T00:55:29	2020-03-22T00:55:29	infra-sb.dicoding.com	infra.monitoring.dicoding.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-12-23T01:55:29.953	2019-12-23T00:55:29	2020-03-22T00:55:29	infra-sb.dicoding.com	infra.monitoring.dicoding.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3