Laravel8 inertia vue how to have Filter on date localized

I am newbie to laravel 8 inertia vue. I changed the locale in .env to 'fr'

Then I created global filters in app.js

Vue.filter('formatDateLong', function(value) {
    if (value) {
      return moment(String(value)).format('LLLL');
    }
  });

  Vue.filter('formatDateShort', function(value) {
    if (value) {
      return moment(String(value)).format('lll');
    }
  });
  Vue.filter('formatDateTimeVeryShort', function(value) {
    if (value) {
      return moment(String(value)).format('ll');
    }
  });

new Vue({
    render: (h) =>
        h(InertiaApp, {
            props: {
                initialPage: JSON.parse(app.dataset.page),
                resolveComponent: (name) => require(`./Pages/${name}`).default,
            },
        }),
}).$mount(app);

In vue template I use thing like this :

{{post.created_at|formatDateLong}} or {{post.created_at|formatDateVeryShort}} 

The filters seems to be applied but unfortunately everything stay in English.

Any idea ?