sets if you want and how to handle errors
the language to use when returning errors. Only has an effect if you use the i18next http middleware, as it relies on req.i18n.changeLanguage to be present. Defaults to auto, which means the a language detector must have detected language and req.t translated to the detected language.
This router implements necessary routes for the content user data (user state) to work. If you only want certain routes, you can specify this in the options parameter.