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

Results forwww.extrava.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2023-01-22T12:12:31.244	2023-01-22T11:12:30	2023-04-22T11:12:29	www.ereconstructive.com	www.extrava.com	C=US, O=Let's Encrypt, CN=R3
2023-01-22T12:12:30.92	2023-01-22T11:12:30	2023-04-22T11:12:29	www.ereconstructive.com	www.extrava.com	C=US, O=Let's Encrypt, CN=R3
2020-01-22T09:11:44.656	2020-01-22T08:11:44	2020-04-21T08:11:44	www.happywithmywife.com	www.extrava.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-01-22T09:11:44.502	2020-01-22T08:11:44	2020-04-21T08:11:44	www.happywithmywife.com	www.extrava.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-01-22T09:10:42.443	2020-01-22T08:10:42	2020-04-21T08:10:42	synpos.com	www.extrava.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-01-22T09:10:42.218	2020-01-22T08:10:42	2020-04-21T08:10:42	synpos.com	www.extrava.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-03-14T21:03:10.771	2019-03-14T20:03:09	2019-06-12T20:03:09	wlq.org	www.extrava.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-03-14T21:03:10.007	2019-03-14T20:03:09	2019-06-12T20:03:09	wlq.org	www.extrava.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3