Add more product categories

[FreddyEE]

Hi

The products on my website have like 2 -3 categories, so I need to push that data into the dataLayer. I thought in this code below, but can't get it done, how to achieve that ?

<?php

/**
 * Lists all product categories and sub-categories in a tree structure.
 *
 * @return array
 */
function list_product_categories() {
    $categories = get_terms(
        array(
            'taxonomy'   => 'product_cat',
            'orderby'    => 'name',
            'hide_empty' => false,
        )
    );

    $categories = treeify_terms($categories);

    return $categories;
}

/**
 * Converts a flat array of terms into a hierarchical tree structure.
 *
 * @param WP_Term[] $terms Terms to sort.
 * @param integer   $root_id Id of the term which is considered the root of the tree.
 *
 * @return array Returns an array of term data. Note the term data is an array, rather than
 * term object.
 */
function treeify_terms($terms, $root_id = 0) {
    $tree = array();

    foreach ($terms as $term) {
        if ($term->parent === $root_id) {
            array_push(
                $tree,
                array(
                    'name'     => $term->name,
                    'slug'     => $term->slug,
                    'id'       => $term->term_id,
                    'count'    => $term->count,
                    'children' => treeify_terms($terms, $term->term_id),
                )
            );
        }
    }

    return $tree;
}