/**
 * Register a line item in HubSpot
 *
 * @access  public
 * @since   1.17
 * @return  int Line Item ID
 */

public function add_line_item( $product ) {

    $line_item_data = array(
        'properties' => array(
            'hs_product_id' => $product['crm_product_id'],
            'name'          => $product['name'],
            'price'         => $product['price'],
            'quantity'      => $product['qty'],
        ),
    );

    /**
     * Filters the deal data.
     *
     * @since 1.17.9
     *
     * @param array $line_item_data The array of data used to create the line item.
     * @param array $product        The product data.
     */

    $line_item_data = apply_filters( 'wpf_ecommerce_hubspot_add_line_item', $line_item_data, $product );

    $params         = wp_fusion()->crm->get_params();
    $params['body'] = json_encode( $line_item_data );
    $response       = wp_remote_post( 'https://api.hubapi.com/crm/v3/objects/line_items', $params );

    if ( is_wp_error( $response ) ) {
        return $response;
    }

    $response = json_decode( wp_remote_retrieve_body( $response ) );

    return $response->id;

}