Add extra customer note on order creation for specific user role in WooCommerce

For a specific user role I want to add a specific customer note to the order.

This is my code:

add_action( 'woocommerce_new_order', 'add_customer_note_user_role' );
function add_customer_note_user_role( $order_id ) {

    $user_info = get_userdata(get_current_user_id());

    if ( $user_info->roles[0]=="administrator" ) {

        $order = wc_get_order( $order_id );

        // The text for the note
        $note = 'This is the message';

        // Add the note
        $order->add_order_note( $note );

        // Save the data
        $order->save();
    }
}

But this puts the message in the wrong place. When you check an order in the backend it's been displayed in the purple message boxes.

I want the message to be displayed as a customer note which is displayed under the shipping address. Because my API is picking up the notes from that place and puts them in our ERP.

I tried to change

$order->add_order_note( $note );

to

$order->add_order_note( $note, 'is_customer_note', true );

But without the desired result, any advice?

To display the message as a customer note displayed below the shipping address, you can use set_customer_note() instead.

So you get:

function action_woocommerce_new_order( $order_id ) {
    // Get the WC_Order Object
    $order = wc_get_order( $order_id );

    // Get the WP_User Object
    $user = $order->get_user();
    
    // Check for "administrator" user roles only
    if ( is_a( $user, 'WP_User' ) && in_array( 'administrator', (array) $user->roles ) ) {
        // The text for the note
        $note = 'This is the message';
        
        // Set note
        $order->set_customer_note( $note );
        
        // Save
        $order->save();
    }
}
add_action( 'woocommerce_new_order', 'action_woocommerce_new_order', 10, 1 );

To keep the original message (when NOT empty) use this instead:

function action_woocommerce_new_order( $order_id ) {
    // Get the WC_Order Object
    $order = wc_get_order( $order_id );

    // Get the WP_User Object
    $user = $order->get_user();
    
    // Check for "administrator" user roles only
    if ( is_a( $user, 'WP_User' ) && in_array( 'administrator', (array) $user->roles ) ) {
        // The text for the note
        $note = 'This is the message';
        
        // Get customer note
        $customer_note = $order->get_customer_note();
        
        // NOT empty
        if ( ! empty ( $customer_note ) ) {
            $note = $customer_note . ' | ' . $note;
        }
        
        // Set note
        $order->set_customer_note( $note );
        
        // Save
        $order->save();
    }
}
add_action( 'woocommerce_new_order', 'action_woocommerce_new_order', 10, 1 );