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

Results fortestcloud.autoprosoftware.net

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2019-01-03T14:16:53.428	2019-01-03T13:16:52	2019-04-03T13:16:52	testcloud1.autoprosoftware.net	testcloud.autoprosoftware.net	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-01-03T14:16:52.42	2019-01-03T13:16:52	2019-04-03T13:16:52	testcloud1.autoprosoftware.net	testcloud.autoprosoftware.net	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-01-03T14:05:25.866	2019-01-03T13:05:25	2019-04-03T13:05:25	testcloud.autoprosoftware.net	testcloud.autoprosoftware.net	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-01-03T14:05:25.147	2019-01-03T13:05:25	2019-04-03T13:05:25	testcloud.autoprosoftware.net	testcloud.autoprosoftware.net	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3