It is possible to enable both the read-only mode of the Zettelstore and authentication/authorization. Both modes are independent of each other. This gives four use cases:

Not read-only, no authorization

Zettelstore runs on your local computer and you only work with it.

Not read-only, with authorization

Zettelstore is accessed remotely. You need authentication to ensure that only valid users access your Zettelstore.

With read-only, no authorization

Zettelstore presents its full content publicly to everyone.

With read-only, with authorization

Nobody is allowed to change the content of the Zettelstore, and only specific zettel should be presented to the public.