Как должен выглядеть AJAX запрос?

EXAMPLE: APPLY COUPON VIA AN URL
Apply coupon through an url like this:
Use the url www.example.com/url-to-shop?apply_coupon=my_coupon
Voila! Any coupon can be applied this way.

$.ajax({
      type: 'GET',
      headers: {
      },
      url: "www.example.com/url-to-shop?apply_coupon=my_coupon",
      data: {},
      response: 'text',
      success: function(data){}
  });