dbosleyjr

1. I followed this per the plugin note: Want to use your own template? Copy all the files from wp-content/plugins/woocommerce-pdf-invoices-packing-slips/templates/Simple to your (child) theme in wp-content/themes/pro-child/woocommerce/pdf/yourtemplate to customize them

and created a new template called SimpleNew

2. I edited the invoice.php file

//replaced:

<tr class=”payment-method”>
<th><?php _e( ‘Payment Method:’, ‘woocommerce-pdf-invoices-packing-slips’ ); ?></th>
<td><?php $this->payment_method(); ?></td>
</tr>

//with:

<tr class=”payment-method”>
<th><?php _e( ‘Payment Method:’, ‘woocommerce-pdf-invoices-packing-slips’ ); ?></th>
<td><?php $this->payment_method(); ?></td>
<th><?php _e( ‘Transaction ID:’, ‘wpo_wcpdf’ ); ?></th>
<td><?php $wpo_wcpdf->custom_field(‘Transaction ID’); ?><?php echo $this->order->get_transaction_id(); ?></td>
</tr>

But it didn’t work!

You have two options:

1. Create a new folder within your main theme to override the email templates (you want to override the templates and not edit the templates directly because once you update the WooCommerce plugin your changes will be lost. See: https://docs.woothemes.com/document/template-structure/

2. Create a child theme (which I highly recommend) and copy the files there to edit. See: https://v4.datafeedr.com/documentation/580