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

Results for*.testing.skilledmatrix.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2021-06-01T08:44:37.938	2021-06-01T07:44:37	2021-08-30T07:44:37	testing.skilledmatrix.com	*.testing.skilledmatrix.com	C=US, O=Let's Encrypt, CN=R3
2021-06-01T08:44:37.938	2021-06-01T07:44:37	2021-08-30T07:44:37	testing.skilledmatrix.com	*.testing.skilledmatrix.com	C=US, O=Let's Encrypt, CN=R3
2021-06-01T08:44:37.482	2021-06-01T07:44:37	2021-08-30T07:44:37	testing.skilledmatrix.com	*.testing.skilledmatrix.com	C=US, O=Let's Encrypt, CN=R3
2021-06-01T08:44:37.482	2021-06-01T07:44:37	2021-08-30T07:44:37	testing.skilledmatrix.com	*.testing.skilledmatrix.com	C=US, O=Let's Encrypt, CN=R3