Add customer full name to receipt

Hi. I would like to know how to add the customer name into the info section of my receipts. I have looked at the examples to edit the functions file in my child theme and have managed to get this far:

// Print Customer Surname on Receipts
function customer_name_order_fields( $fields, $order ) {
    $new_fields = array();
        
    if( get_post_meta( $order->get_ID(), 'billing_last_name', true ) ) {
        $new_fields['billing_last_name'] = array( 
            'label' => 'Customer Surname',
            'value' => get_post_meta( $order->get_ID(), 'billing_last_name', true )
        );
    }
    
    
    return array_merge( $fields, $new_fields );
}
add_filter( 'wcdn_order_info_fields', 'example_custom_order_fields', 10, 2 );

…I used this example to see if I could start with getting just the surname, but even that didn’t work. I wondered if anyone might be a lot more clever than me :0)