To whom it may concern. I tweaked this plugin to show the VAT which is essential in the Italian tax system.
I am using the following plugin to add VAT but I renamed the variable of VAT to campo_cf_piva: https://www.netstarsolution.net/woocommerce-partita-iva-e-codice-fiscale-free/
So I added the following code to the Woocommerce pdf invoices packing slips template:
<div class="recipient-address">Codice fiscale: <?php
$campo_cf_piva = get_post_meta($wpo_wcpdf->export->order->id,'campo_cf_piva',true);
if (isset($campo_cf_piva)) {
echo $campo_cf_piva;
}
?></div>
I hope I made myself understood.