Display custom data on Woocommerce admin order pre

I would like to add some custom data to the end of the preview order in Woocommerce order listing page.

For that I have tried the hook 'woocommerce_admin_order_preview_end'. But no way to pass any arguments to that action.

add_action( 'woocommerce_admin_order_preview_end', 'custom_display_order_data_in_admin' );
function custom_display_order_data_in_admin( $order ){
    //$order is empty here
}

Does anybody have an idea on this? I'm stuck on this.

You can't get the order object as it's a template that loads specific data via Ajax and there is no arguments for woocommerce_admin_order_preview_end action hook.

Instead the filter hook woocommerce_admin_order_preview_get_order_details will allow you first to add some custom data that you will be able to call and display it after in woocommerce_admin_order_preview_end action hook.

The code:

// Add custom order meta data to make it accessible in Order preview template
add_filter( 'woocommerce_admin_order_preview_get_order_details', 'admin_order_preview_add_custom_meta_data', 10, 2 );
function admin_order_preview_add_custom_meta_data( $data, $order ) {
    // Replace '_custom_meta_key' by the correct postmeta key
    if( $custom_value = $order->get_meta('_custom_meta_key') )
        $data['custom_key'] = $custom_value; // <= Store the value in the data array.

    return $data;
}

// Display custom values in Order preview
add_action( 'woocommerce_admin_order_preview_end', 'custom_display_order_data_in_admin' );
function custom_display_order_data_in_admin(){
    // Call the stored value and display it
    echo '<div>Value: {{data.custom_key}}</div><br>';
}

Code goes in function.php file of your active child theme (or active theme). Tested and works.