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

Results forcarstr.de

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2019-05-25T03:44:30.866	2019-05-25T02:44:29	2019-08-23T02:44:29	www.bombaydripp.com	dev.carstr.de	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-05-25T03:44:29.786	2019-05-25T02:44:29	2019-08-23T02:44:29	www.bombaydripp.com	dev.carstr.de	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-03-26T13:14:26.746	2019-03-26T12:14:26	2019-06-24T12:14:26	dev.carstr.de	dev.carstr.de	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-03-26T13:14:26.168	2019-03-26T12:14:26	2019-06-24T12:14:26	dev.carstr.de	dev.carstr.de	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-03-26T09:35:51.364	2019-03-26T08:35:49	2019-06-24T08:35:49	dev.carstr.de	dev.carstr.de	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-03-26T09:35:50.02	2019-03-26T08:35:49	2019-06-24T08:35:49	dev.carstr.de	dev.carstr.de	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3