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

Results forapp.cargoconnect.cloud

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2019-02-18T04:44:53.766	2019-02-18T03:44:52	2019-05-19T03:44:52	johnnysainz.com	app.cargoconnect.cloud	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-02-18T04:44:52.453	2019-02-18T03:44:52	2019-05-19T03:44:52	johnnysainz.com	app.cargoconnect.cloud	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2018-12-21T08:14:19.546	2018-12-21T07:14:18	2019-03-21T07:14:18	app.cargoconnect.cloud	app.cargoconnect.cloud	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2018-12-21T08:14:18.668	2018-12-21T07:14:18	2019-03-21T07:14:18	app.cargoconnect.cloud	app.cargoconnect.cloud	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2018-12-21T04:56:09.64	2018-12-21T03:56:09	2019-03-21T03:56:09	app.cargoconnect.cloud	app.cargoconnect.cloud	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2018-12-21T04:56:09.198	2018-12-21T03:56:09	2019-03-21T03:56:09	app.cargoconnect.cloud	app.cargoconnect.cloud	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3