EmberJS and custom endpoints urls

I'm working with EmberJS version 2.14.2 for frontend and I have Rails API backend. I want to get some data from backend but auto-generated url is different from my API endpoint.

the difference is: emberJS generates /admins/api/v1/domains but my endpoint is actually /admins/api/v1/domains.json

how can I achive this in EmberJS? how can i define a totally different endpoint for some models?

my adapter:

import DS from 'ember-data';

export default DS.JSONAPIAdapter.extend({
  host: 'http://localhost:4000',
  namespace: 'admins/api/v1',
  session: Ember.inject.service('session'),

  headers: Ember.computed('session.access_token', function() {
    return {
      'Authorization': "Bearer " + this.get('session.access_token')
    };
  })
});

my model:

import DS from 'ember-data';

export default DS.Model.extend({
  host: DS.attr(), 
  layout: DS.attr(), 
  token: DS.attr(), 
  created_at: DS.attr(), 
  updated_at: DS.attr()
});

Is it possible to define a custom endpoint in EmberJS? I really checked the documentation and there is nothing there.

Plz halp