A function whose declared type is neither 'undefined', 'void', nor 'any' must return a value.

Argument of type 'string | undefined' is not assignable to parameter of type '"exhibition-guides" | "articles" | "books" | "event-series" | "events" | "exhibitions" | "guides" | "pages" | "projects" | "seasons" | "series" | "webcomics" | "guide-formats" | ... 16 more ... | "exhibition-guides-links"'.