You did not mention if it was a domain password  prompt or a basic
authentication prompt. Please let us know if the prompt asks for Username,
password, and domain or just a username and password.

Please let us know which type and we can suggest additional tips.

The authentication that requests  user, password  and domain because in
the IIS the anonymous access  is disabled intentionally.
But I need that a dashboard  site will be publish for everybody
(readers) without requesting user and password. At the same time the
authors can be authenticated  somehow to consent to the place without
has integrated authentication.