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

Results forwww.courses.microprogramers.org

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2023-02-20T07:20:55.422	2023-02-20T06:20:54	2023-05-21T06:20:53	courses.microprogramers.org	www.courses.microprogramers.org	C=US, O=Let's Encrypt, CN=R3
2023-02-20T07:20:55.093	2023-02-20T06:20:54	2023-05-21T06:20:53	courses.microprogramers.org	www.courses.microprogramers.org	C=US, O=Let's Encrypt, CN=R3
2022-12-21T06:06:03.805	2022-12-21T05:06:02	2023-03-21T05:06:01	courses.microprogramers.org	www.courses.microprogramers.org	C=US, O=Let's Encrypt, CN=R3
2022-12-21T06:06:03.159	2022-12-21T05:06:02	2023-03-21T05:06:01	courses.microprogramers.org	www.courses.microprogramers.org	C=US, O=Let's Encrypt, CN=R3
2022-12-12T15:31:47.82	2022-12-12T14:31:47	2023-03-12T14:31:46	www.courses.microprogramers.org	www.courses.microprogramers.org	C=US, O=Let's Encrypt, CN=R3
2022-12-12T15:31:47.478	2022-12-12T14:31:47	2023-03-12T14:31:46	www.courses.microprogramers.org	www.courses.microprogramers.org	C=US, O=Let's Encrypt, CN=R3