Returning 401 Unauthorized even the adapter is created

The request returned a 401 Unauthorized for GET /foos. From the guide that I read earlier, https://guides.emberjs.com/release/models/customizing-adapters/ it stated that the host name must defined

Question: WHy is it returning 401?

My app/adapters/application.js

  import JSONAPIAdapter from '@ember-data/adapter/json-api';

  export default class ApplicationAdapter extends JSONAPIAdapter {
    namespace = 'api/v1';
    host = 'https://someUrl.com';
  }

and my app/models/foo.js is

import Model, { attr } from '@ember-data/model';

export default class FoowModel extends Model {
  @attr('string') landmark;
};

and my app/routes/welcome.js is

import Route from '@ember/routing/route';

export default class WelcomeRoute extends Route {
  model() {
    return this.store.findAll('foo');
  }
}