To see what will drupalSettings output you can put console log in drupalSettingsLoader.js and this will give you info what is present in drupalSettings vars that is drupal pushing to JS
if (settingsElement !== null) {
window.drupalSettings = JSON.parse(settingsElement.textContent);
console.log(window.drupalSettings);
}
you can also always call console.log (drupalSettings); in browser console and check out what is in.