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

Results forshfc-staging.happycode.nl

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2019-04-19T16:00:21.904	2019-04-19T15:00:20	2019-07-18T15:00:20	configurator-poc.happycode.nl	shfc-staging.happycode.nl	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-04-19T16:00:20.517	2019-04-19T15:00:20	2019-07-18T15:00:20	configurator-poc.happycode.nl	shfc-staging.happycode.nl	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-02-18T13:33:33.668	2019-02-18T12:33:32	2019-05-19T12:33:32	configurator-poc.happycode.nl	shfc-staging.happycode.nl	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-02-18T13:33:32.854	2019-02-18T12:33:32	2019-05-19T12:33:32	configurator-poc.happycode.nl	shfc-staging.happycode.nl	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3