How can I access my Rails backend API information in my Ember client side?

I'm a beginner at coding and I'm working on this tutorial right now and I'm having a bit of trouble. I would really appreciate some help!

Here's my problem: I'm using an external API in my Rails backend. I'm not using a model. But the tutorial is asking me to access a model in this section when I want to access my API information from my Rails class.

This is what they want me to do:

Library.BooksRoute = Ember.Route.extend({
   model: function() {
   return this.get('store').find('book');
  }
 });

How can I change that code to access my API? I'm using HTTP party.

Here's a bit of what my activities controller looks like:

class BooksController < ApplicationController
  respond_to :json
  include HTTParty
  base_uri ''   # took this out
  def index
    render json: self.class.get("")  # took out my link with API key here
  end
end

Thanks in advance!