WooCommerce: Add reference ID in BACS Payment Method - Bank Details (Displayed on confirmation E-mail and Thank You Page)

functions.php

/**
 * WooCommerce: Add reference ID in BACS Payment Method - Bank Details (Displayed on confirmation E-mail and Thank You Page)
 * Author: MarioMarkovic.com
 */
add_filter( 'woocommerce_bacs_account_fields', 'custom_bacs_account_field', 10, 2);
function custom_bacs_account_field( $account_fields, $order_id ) {
    $order = wc_get_order( $order_id );

    $account_fields['reference_no' ] = array(
        'label' => "Reference No.",
        'value' => $order->get_id()
    );
    return $account_fields;
}