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

Results forforge.toolpar.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2021-08-15T06:41:25.058	2021-08-15T05:41:24	2021-11-13T05:41:22	forge.toolpar.com	forge.toolpar.com	C=US, O=Let's Encrypt, CN=R3
2021-08-15T06:41:24.912	2021-08-15T05:41:24	2021-11-13T05:41:22	forge.toolpar.com	forge.toolpar.com	C=US, O=Let's Encrypt, CN=R3
2021-05-13T16:47:38.077	2021-05-13T15:47:37	2021-08-11T15:47:37	forge.toolpar.com	forge.toolpar.com	C=US, O=Let's Encrypt, CN=R3
2021-05-13T16:47:37.945	2021-05-13T15:47:37	2021-08-11T15:47:37	forge.toolpar.com	forge.toolpar.com	C=US, O=Let's Encrypt, CN=R3
2021-03-30T15:07:42.246	2021-03-30T00:00:00	2021-06-28T23:59:59	forge.toolpar.com	forge.toolpar.com	C=AT, O=ZeroSSL, CN=ZeroSSL RSA Domain Secure Site CA
2021-03-30T15:07:40.858	2021-03-30T00:00:00	2021-06-28T23:59:59	forge.toolpar.com	forge.toolpar.com	C=AT, O=ZeroSSL, CN=ZeroSSL RSA Domain Secure Site CA