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

Results forwebdisk.server1.prosdian.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2021-07-05T11:24:27.552	2021-07-05T10:24:27	2021-10-03T10:24:26	server1.prosdian.com	*.server1.prosdian.com	C=US, O=Let's Encrypt, CN=R3
2021-07-05T11:24:27.151	2021-07-05T10:24:27	2021-10-03T10:24:26	server1.prosdian.com	*.server1.prosdian.com	C=US, O=Let's Encrypt, CN=R3
2020-12-05T09:39:57.294	2020-12-05T08:39:57	2021-03-05T08:39:57	server1.prosdian.com	*.server1.prosdian.com	C=US, O=Let's Encrypt, CN=R3
2020-12-05T09:39:57.097	2020-12-05T08:39:57	2021-03-05T08:39:57	server1.prosdian.com	*.server1.prosdian.com	C=US, O=Let's Encrypt, CN=R3
2020-12-05T09:10:32.637	2020-12-05T08:10:32	2021-03-05T08:10:32	server1.prosdian.com	webdisk.server1.prosdian.com	C=US, O=Let's Encrypt, CN=R3
2020-12-05T09:10:32.36	2020-12-05T08:10:32	2021-03-05T08:10:32	server1.prosdian.com	webdisk.server1.prosdian.com	C=US, O=Let's Encrypt, CN=R3
2020-12-05T09:04:20.919	2020-12-05T08:04:20	2021-03-05T08:04:20	server1.prosdian.com	*.server1.prosdian.com	C=US, O=Let's Encrypt, CN=R3
2020-12-05T09:04:20.648	2020-12-05T08:04:20	2021-03-05T08:04:20	server1.prosdian.com	*.server1.prosdian.com	C=US, O=Let's Encrypt, CN=R3