Switch Library to Audiobook type

Hi since a few updates Symfonium supports audiobooks which is awesome! In the chsngelogs iz states that

However I cannot find this setting anywhere. Is it hidden and only used for Audiobookshelf at the time? For instance I have a navidrome instance that has two libraries. One is Music, the other is Audiobooks. So it would great if one could change one of the two navidrome libraries to Audiobook type. Am I missing something? I couldnt find that in the settings.

Settings > Manage Media Providers > (Edit a provider)

Thanks, it seems to be the provider then. It does not work for jellyfin or navidrome, yet.