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

Results forstore.admin.smartlinkgo.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2021-09-22T20:08:20.863	2021-09-22T19:08:20	2021-12-21T19:08:19	store.admin.smartlinkgo.com	store.admin.smartlinkgo.com	C=US, O=Let's Encrypt, CN=R3
2021-09-22T20:08:20.404	2021-09-22T19:08:20	2021-12-21T19:08:19	store.admin.smartlinkgo.com	store.admin.smartlinkgo.com	C=US, O=Let's Encrypt, CN=R3
2021-01-29T14:07:27.003	2021-01-29T13:07:26	2021-04-29T13:07:26	store.admin.smartlinkgo.com	store.admin.smartlinkgo.com	C=US, O=Let's Encrypt, CN=R3
2021-01-29T14:07:26.831	2021-01-29T13:07:26	2021-04-29T13:07:26	store.admin.smartlinkgo.com	store.admin.smartlinkgo.com	C=US, O=Let's Encrypt, CN=R3