Add custom Fields

Hi,

I am trying to add MPN and Brand to the feed, but both those fields are custom fields. Is it possible?

Please see screenshot here:
https://www.evernote.com/l/ASF8tES5lIpOwKzhhx1ICf-QoHQ53JJ1Efs

And this is how I added the fields in my function.php

Thank you

<?php
// Display Fields
add_action( 'woocommerce_product_options_general_product_data', 'woo_add_custom_general_fields' );

// Save Fields
add_action( 'woocommerce_process_product_meta', 'woo_add_custom_general_fields_save' );

// Add New Fields
function woo_add_custom_general_fields() {
    global $woocommerce, $post;
    echo '<div class="options_group">';

    woocommerce_wp_text_input(
        array(
            'id'          => '_mpn',
            'label'       => __( 'MPN', 'woocommerce' ),
        )
    );

    woocommerce_wp_text_input(
        array(
            'id'          => '_brand',
            'label'       => __( 'Brand', 'woocommerce' ),
            'placeholder' => 'ie Samsung',
        )
    );

    echo '</div>';
}

// Saving Field Values
function woo_add_custom_general_fields_save( $post_id ){

    $woocommerce_text_field = $_POST['_mpn'];
    if( !empty( $woocommerce_text_field ) )
        update_post_meta( $post_id, '_mpn', esc_attr( $woocommerce_text_field ) );

    $woocommerce_text_field = $_POST['_brand'];
    if( !empty( $woocommerce_text_field ) )
        update_post_meta( $post_id, '_brand', esc_attr( $woocommerce_text_field ) );
 }
 ?>

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