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

Results foreventweb.thirddegree.app

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2019-06-16T09:44:08.27	2019-06-16T08:44:07	2019-09-14T08:44:07	instantchat.io	eventweb.thirddegree.app	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-06-16T09:44:07.902	2019-06-16T08:44:07	2019-09-14T08:44:07	instantchat.io	eventweb.thirddegree.app	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-04-16T11:16:25.93	2019-04-16T10:16:25	2019-07-15T10:16:25	neverskiplegday.ca	eventweb.thirddegree.app	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-04-16T11:16:25.463	2019-04-16T10:16:25	2019-07-15T10:16:25	neverskiplegday.ca	eventweb.thirddegree.app	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-02-14T07:43:59.152	2019-02-14T06:43:57	2019-05-15T06:43:57	polished.app	eventweb.thirddegree.app	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-02-14T07:43:57.993	2019-02-14T06:43:57	2019-05-15T06:43:57	polished.app	eventweb.thirddegree.app	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-02-14T06:10:23.523	2019-02-14T05:10:22	2019-05-15T05:10:22	eventweb.thirddegree.app	eventweb.thirddegree.app	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-02-14T06:10:22.661	2019-02-14T05:10:22	2019-05-15T05:10:22	eventweb.thirddegree.app	eventweb.thirddegree.app	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3