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

Results forgitlab.dev.arkive.ai

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2020-09-26T13:27:38.393	2020-09-26T12:27:38	2020-12-25T12:27:38	gitlab.dev.arkive.ai	gitlab.dev.arkive.ai	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-09-26T13:27:38.244	2020-09-26T12:27:38	2020-12-25T12:27:38	gitlab.dev.arkive.ai	gitlab.dev.arkive.ai	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-09-26T12:28:33.631	2020-09-26T11:28:33	2020-12-25T11:28:33	gitlab.dev.arkive.ai	gitlab.dev.arkive.ai	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-09-26T12:28:33.436	2020-09-26T11:28:33	2020-12-25T11:28:33	gitlab.dev.arkive.ai	gitlab.dev.arkive.ai	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-09-25T03:20:23.799	2020-09-25T02:20:23	2020-12-24T02:20:23	gitlab.dev.arkive.ai	gitlab.dev.arkive.ai	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-09-25T03:20:23.56	2020-09-25T02:20:23	2020-12-24T02:20:23	gitlab.dev.arkive.ai	gitlab.dev.arkive.ai	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-09-21T03:12:17.638	2020-09-21T02:12:17	2020-12-20T02:12:17	gitlab.dev.arkive.ai	gitlab.dev.arkive.ai	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-09-21T03:12:17.433	2020-09-21T02:12:17	2020-12-20T02:12:17	gitlab.dev.arkive.ai	gitlab.dev.arkive.ai	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3