not customer notes, but PURCHASE NOTES. It shown below each product (if exists) in mails for customers, but not for admin.
I found it in email-order-items.php
// Show purchase note
$purchase_note = '';
if ( $product && $product->get_purchase_note() ) {
$purchase_note = $product->get_purchase_note();
}
if ( ( 'customer_on_hold_order' === $this->template
|| 'customer_processing_order' === $this->template
|| 'customer_completed_order' === $this->template
|| 'customer_refunded_order' === $this->template
|| 'customer_invoice' === $this->template
|| 'customer_note' === $this->template )
&& isset( $args['show_purchase_note'] )
&& is_object( $product )
&& ! empty( $purchase_note )
)
If i just add custom row
|| ‘new_order’ === $this->template
it works, BUT how can i add it by snippets to avoid resetting my changes after plugin updates.