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

Results fortoolbox.bigfm.de

Resolver

Location

A

Name	TTL	Value
toolbox.bigfm.de	600	151.101.1.195Fastly, Inc.
toolbox.bigfm.de	600	151.101.65.195Fastly, Inc.

Name	TTL	Value
toolbox.bigfm.de	300	0 issue "letsencrypt.org "
toolbox.bigfm.de	300	0 issue "pki.goog "