to with Hashtag as first sign in Sub

I'm new here.
I'm trying to route a subdomain to a serivce that first has a # hashtag character as an identifier.
(public) to (static none docker webserver)
I always get a 404 message.
Is this not possible or does the # character have to be masked?
Without the # its works.
Many thanks for your help

Fragments (the # and following text ) are not sent by web clients to a server. So the rule will never match.

Fragments depend on the document MIME type and are evaluated by the client (web browser). Clients are not supposed to send URI fragments to servers when they retrieve a document, and without help from a local application (see below) fragments do not participate in HTTP redirections.[1]