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

Results fordev.siologic.pro

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2019-05-07T04:44:25.222	2019-05-07T03:44:23	2019-08-05T03:44:23	techturtles.co	dev.siologic.pro	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-05-07T04:44:23.996	2019-05-07T03:44:23	2019-08-05T03:44:23	techturtles.co	dev.siologic.pro	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-03-07T19:45:06.834	2019-03-07T18:45:06	2019-06-05T18:45:06	akramgassem.com	dev.siologic.pro	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-03-07T19:45:06.096	2019-03-07T18:45:06	2019-06-05T18:45:06	akramgassem.com	dev.siologic.pro	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-03-07T17:39:06.052	2019-03-07T16:39:04	2019-06-05T16:39:04	dev.siologic.pro	dev.siologic.pro	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-03-07T17:39:04.711	2019-03-07T16:39:04	2019-06-05T16:39:04	dev.siologic.pro	dev.siologic.pro	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3