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

Results forwww.firebase.cloud

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2025-03-31T23:23:43.386	2025-03-31T21:56:43	2026-03-31T21:56:43	www.firebase.cloud	www.firebase.cloud	C=US, ST=Arizona, L=Scottsdale, O="GoDaddy.com, Inc.", OU=http://certs.godaddy.com/repository/, CN=Go Daddy Secure Certificate Authority - G2
2025-03-31T21:56:43.975	2025-03-31T21:56:43	2026-03-31T21:56:43	www.firebase.cloud	www.firebase.cloud	C=US, ST=Arizona, L=Scottsdale, O="GoDaddy.com, Inc.", OU=http://certs.godaddy.com/repository/, CN=Go Daddy Secure Certificate Authority - G2
2017-10-14T21:44:01.772	2017-10-14T20:43:28	2018-01-12T20:43:28	lapopulartortilleria.com	www.firebase.cloud	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2017-10-14T19:36:20.756	2017-10-14T18:36:18	2018-01-12T18:36:18	www.firebase.cloud	www.firebase.cloud	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3