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

Results forwww.stag-admin.getsitekit.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2025-04-04T08:28:28.079	2025-04-04T07:29:56	2025-07-03T07:29:55	stag-admin.getsitekit.com	stag-admin.getsitekit.com	C=US, O=Let's Encrypt, CN=R11
2025-04-04T08:28:26.849	2025-04-04T07:29:56	2025-07-03T07:29:55	stag-admin.getsitekit.com	stag-admin.getsitekit.com	C=US, O=Let's Encrypt, CN=R11
2018-09-14T09:24:05.343	2018-09-14T08:24:04	2018-12-13T08:24:04	stag-admin.getsitekit.com	stag-admin.getsitekit.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2018-09-14T09:24:04.697	2018-09-14T08:24:04	2018-12-13T08:24:04	stag-admin.getsitekit.com	stag-admin.getsitekit.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3