Invoice Data

I need to insert the date of invoice in the invoice. Can you help?

function print_order_add_invoice_date( $fields, $order ) {
	$new_fields = array();

	$order_invoice_date = wcdn_get_order_invoice_date( $order->id );
	if( $order_invoice_date ) {
		$new_fields['order_invoice_date'] = array(
			'label' => __( 'Invoice Date' ),
			'value' => $order_invoice_date
		);
	}

	return array_merge( $fields, $new_fields );
}
add_filter( 'wcdn_order_info_fields', 'print_order_add_invoice_date', 10, 2 );

Could you please specify in what file and where exactly this code needs to be added? – Thanks for your help

As always: functions.php

Unfortunatly this shows the “Invoice Date” on both the order slip and the invoice slip. It only should show on the invoice.

use the wcdn_get_template_type() to check the type of template.

function print_order_add_invoice_date( $fields, $order ) {
$new_fields = array();

if( wcdn_get_template_type() == 'invoice' ) {
	$order_invoice_date = wcdn_get_order_invoice_date( $order->id );
	if( $order_invoice_date ) {
		$new_fields['order_invoice_date'] = array(
			'label' => __( 'Invoice Date' ),
			'value' => $order_invoice_date
		);
	}
}

return array_merge( $fields, $new_fields );
}
add_filter( 'wcdn_order_info_fields', 'print_order_add_invoice_date', 10, 2 );