[Plugin: marketpress] get category id from product

hi!
I have created a metabox with ‘mp_dropdown_categories’ content.
The code is here, located in template-functions.php
———————————–
add_action( ‘add_meta_boxes’, ‘cd_meta_box_add’ );
function cd_meta_box_add()
{
add_meta_box( ‘my-meta-box-id’, ‘Gerar catalogo’, ‘cd_meta_box_cb’, ‘product’, ‘side’, ‘high’ );
}

function cd_meta_box_cb()
{
mp_dropdown_categories();
?>
“>gerar catalogo<?php
}
————————————–
This metabox appears in Edit’ and Create new product area and its showing a dropdown list of all categories.
My problem is: how can I get the category ID of each category and category ID of current product?
Cause i need the ID to send via _GET to other php file.(external to wordpress)

I apreciate any help cause im new in marketpress structure. Thanks!!

https://www.ads-software.com/extend/plugins/marketpress/