[Vuejs]-500 localStorage is not defined nuxt js

localStorage object is under window, which only exists on the client side.

I have used cookie-universal-nuxt in Nuxt 2 to share the cookies between server and client for auth purposes.

As @justanotherpeter mentioned, you can only use localStorage on the client side. Alternatively, you can use cookies for your authentication. Nuxt 3 has useCookie composable.