Empty response to Postmaster_Package::fit()

[tagbb]

Good day,

I am a web programmer at a technology company. I have integrated with your Postmaster API for several of our client’s sites using your PHP library, and we love that it makes shipping integrations so much easier! I have used the address validation and shipping rate API calls with great success. However, I am having trouble with the optimal package fitting API call. I am using the exact same example you have on your site here:

https://www.postmaster.io/docs/api#fitbox

---

$result = Postmaster_Package::fit(array(

"items" => array(

array("width" => 2.2, "length" => 3, "height" => 1, "count" => 2, "sku" => "123ABC"),

),

"packages" => array(

array("width" => 6, "length" => 6, "height" => 6),

array("width" => 12, "length" => 12, "height" => 12),

),

));

---

However, for some reason I am getting back empty arrays instead of the response posted on your site. I am getting back:

---

[leftovers] => Array
(
)

[boxes] => Array
    (
    )

[all_fit] => 1

)

---

We would really appreciate your assistance for continued use of your great service. Thank you in advance!