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

Results forwww.api-central.digitalpool.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2023-11-03T20:14:17.42	2023-11-03T19:14:16	2024-02-01T19:14:15	api-central.digitalpool.com	api-central.digitalpool.com	C=US, O=Let's Encrypt, CN=E1
2023-11-03T20:14:17.005	2023-11-03T19:14:16	2024-02-01T19:14:15	api-central.digitalpool.com	api-central.digitalpool.com	C=US, O=Let's Encrypt, CN=E1
2023-11-03T20:14:11.406	2023-11-03T19:14:11	2024-02-01T19:14:10	api-central.digitalpool.com	api-central.digitalpool.com	C=US, O=Let's Encrypt, CN=R3
2023-11-03T20:14:11.201	2023-11-03T19:14:11	2024-02-01T19:14:10	api-central.digitalpool.com	api-central.digitalpool.com	C=US, O=Let's Encrypt, CN=R3