tethys/resources/js/bootstrap.js

window._ = require('lodash');

/**
 * We'll load the axios HTTP library which allows us to easily issue requests
 * to our Laravel back-end. This library automatically handles sending the
 * CSRF token as a header based on the value of the "XSRF" token cookie.
 */
try {
    window.$ = window.jQuery = require('jquery');
    // require('bootstrap-sass');
} catch (e) {}

window.axios = require('axios');
window.axios.defaults.headers.common['X-Requested-With'] = 'XMLHttpRequest';

/**
 * Next we will register the CSRF Token as a common header with Axios so that
 * all outgoing HTTP requests automatically have it attached. This is just
 * a simple convenience so we don't have to attach every token manually.
 */

let token = document.head.querySelector('meta[name="csrf-token"]');

if (token) {
    window.axios.defaults.headers.common['X-CSRF-TOKEN'] = token.content;
} 
else {
    console.error('CSRF token not found: https://laravel.com/docs/csrf#csrf-x-csrf-token');
}