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

Results foreditor.stellar1.spunk.link

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2021-09-26T13:08:16.51	2021-09-24T19:15:32	2021-12-23T19:15:31	andreadiscanni.com	editor.stellar1.spunk.link	C=US, O=Google Trust Services LLC, CN=GTS CA 1D4
2021-09-24T20:20:50.959	2021-09-24T19:15:32	2021-12-23T19:15:31	andreadiscanni.com	editor.stellar1.spunk.link	C=US, O=Google Trust Services LLC, CN=GTS CA 1D4
2021-08-01T10:07:25.464	2021-07-29T14:17:17	2021-10-27T15:17:17	wavers.io	editor.stellar1.spunk.link	C=US, O=Google Trust Services LLC, CN=GTS CA 1D4
2021-07-29T15:19:39.148	2021-07-29T14:17:17	2021-10-27T15:17:17	wavers.io	editor.stellar1.spunk.link	C=US, O=Google Trust Services LLC, CN=GTS CA 1D4
2021-07-29T10:41:35.949	2021-07-29T09:41:35	2021-10-27T09:41:33	editor.stellar1.spunk.link	editor.stellar1.spunk.link	C=US, O=Let's Encrypt, CN=R3
2021-07-29T10:41:35.764	2021-07-29T09:41:35	2021-10-27T09:41:33	editor.stellar1.spunk.link	editor.stellar1.spunk.link	C=US, O=Let's Encrypt, CN=R3