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

Results for2544610g10.secure0160.hubspot.net

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2020-07-04T07:49:26.127	2020-07-04T00:00:00	2021-07-04T12:00:00	2544610g10.secure0160.hubspot.net	2544610g10.secure0160.hubspot.net	C=US, O="Cloudflare, Inc.", CN=Cloudflare Inc ECC CA-3
2020-07-04T07:49:25.34	2020-07-04T00:00:00	2021-07-04T12:00:00	2544610g10.secure0160.hubspot.net	2544610g10.secure0160.hubspot.net	C=US, O="Cloudflare, Inc.", CN=Cloudflare Inc RSA CA-2
2020-01-08T19:51:44.838	2020-01-08T00:00:00	2020-10-09T12:00:00	2544610g10.secure0160.hubspot.net	2544610g10.secure0160.hubspot.net	C=US, ST=CA, L=San Francisco, O="CloudFlare, Inc.", CN=CloudFlare Inc ECC CA-2
2020-01-08T19:51:43.828	2020-01-08T00:00:00	2020-10-14T12:00:00	2544610g10.secure0160.hubspot.net	2544610g10.secure0160.hubspot.net	C=US, ST=CA, L=San Francisco, O="CloudFlare, Inc.", CN=CloudFlare Inc RSA CA-1