Add VAT number to the Shipment documents From Address using WebToffee Print invoice and packing slip plugin

functions.php

 add_filter( 'wf_alter_shipmentlabel_from_address', 'wf_new_shipping_from_address_format',10,3 );
 
 function wf_new_shipping_from_address_format($original_address_format,$order,$from_address)
 {  
 
  $original_address_format .= '<br/>'; 
  $original_address_format .= 'GSTIN:'; 
  $original_address_format .= '12345676787'; 
  $original_address_format .= '<br/>'; 
  
  return $original_address_format;
}