Hi~ another solution I found, pagination this time.
Very very simple, just add the code
Page {PAGENO} of {nb}
No ’ " <> needed.
Here is an example.
<header class="clearfix">
<div id="logo">
<?php echo invoice_logo_pdf(); ?>
</div>
Page {PAGENO} of {nb}
</header>
Preferably you may want to add this in the header section. You can refer to this thread for details: (…yes, it’s me as well 
)
https://community2.invoiceplane.com/t/topic/3561