Do i need pro to add this

I’ve add a line of code to the packing-slip.php file but the only thing i see on PDF is the comments. This is from WooComm Custom Fields Pro extension. Wondering if i need pro version of your plug to make this work.

/* This is custom code to print SK CUSTOM CHEKCOUT FIELDS on Packing Slip  */
<?php wccf_print_checkout_field_value(array('key' => 'pickuplocations' )); ?>

Thanks.