Shopify order API returns OK but does not update order using JS

I’m trying to create an order using JS. I’ve authenticated my app and have a function that POST’s to orders.json. I see a status code of 200, indicating that the request submitted OK (right?) but the order itself never gets created. I’ve heard something about disabling cookies in my request, but I don’t know how to do that, so if that’s what I need to do please let me know.

I’m putting up my entire function, since I’m new to this entire thing and it seems that it’s probably the structure of my request, not the API call. I’m seeing the “Error” log in the console, so clearly the error function is running.

function submitShuffle(prodid)
{
  console.log(prodid);
  var params = {
    "order": {
        "line_items": [
        {
            "variant_id": prodid,
            "quantity": 1
        }
      ]
    }
    };
    $.ajax({
      type: 'POST',
      url: 'https://<my-usrnam>:<my-pass>@toyboxshufflesandbox.myshopify.com/admin/orders.json',
      dataType: 'application/json',
      data: params,
      success: function(data){
        console.log(data);
      },
      error: function(data){
        console.log("Error");
        console.log(data);}
    });
}