Use localization with vue

After doing some research I saw a couple people recommend this library https://github.com/kg-bot/laravel-localization-to-vue .

And I'm a little confused on how to actually use it, I'm also using inertia.js so the part where they change the app.js has me a bit confused. This is my app.js code, I'm using the lang from Element-ui so I'm not sure how to add the code they use to this.

import {InertiaApp} from '@inertiajs/inertia-vue'
import Vue from 'vue'
import ElementUI from 'element-ui'
import lang from 'element-ui/lib/locale/lang/es'
import 'element-ui/lib/theme-chalk/reset.css'
import locale from 'element-ui/lib/locale'

locale.use(lang);
Vue.use(InertiaApp);
Vue.use(ElementUI);

const app = document.getElementById('app');
app.setAttribute(':class',"{'loaded': loaded}");
new Vue({
    render: h => h(InertiaApp, {
        props: {
            initialPage: JSON.parse(app.dataset.page),
            resolveComponent: name => import(`@/Pages/${name}`).then(module => module.default),
        },
        data(){
            return{
                loaded:true
            }
        }
    }),
}).$mount(app);

I'm also confused about changing the locale, I want to use some flag icons to change the locale and translate accordingly.