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

Results forsso-dev.solutionmag.cloud

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2019-02-25T18:44:14.672	2019-02-25T17:44:14	2019-05-26T17:44:14	www.insta-coin.co.uk	sso-dev.solutionmag.cloud	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-02-25T18:44:14.062	2019-02-25T17:44:14	2019-05-26T17:44:14	www.insta-coin.co.uk	sso-dev.solutionmag.cloud	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-02-25T17:08:16.932	2019-02-25T16:08:15	2019-05-26T16:08:15	sso-dev.solutionmag.cloud	sso-dev.solutionmag.cloud	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-02-25T17:08:15.761	2019-02-25T16:08:15	2019-05-26T16:08:15	sso-dev.solutionmag.cloud	sso-dev.solutionmag.cloud	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3