function my_custom_export() {

    $args = array(
        'numberposts' => - 1,
        'post_type'   => 'shop_order',
        'post_status' => array( 'wc-processing', 'wc-completed' ),
        'fields'      => 'ids',
        'meta_query'  => array(
            array(
                'key'     => 'wpf_complete',
                'compare' => 'NOT EXISTS',
            ),
        ),
        'date_query'  => array(
            'after' => 'March 1 2020',
        ),
    );

    $orders = get_posts( $args );

    return $orders;

}

add_filter( 'wpf_batch_woocommerce_init', 'my_custom_export', 20 );