How to Add an Attachment in
WooCommerce Order Emails

To add an attachment to your order emails, open the functions.php file of your child theme and add the following snippet of code:

/**
 * Add Attachment in WooCommerce Order Emails
 * More tips: https://themes.email/woocommerce.html
 */

add_filter( 'woocommerce_email_attachments', 'attach_to_wc_emails', 10, 3);

function attach_to_wc_emails ( $attachments , $id, $object ) {

	$file_path = get_template_directory() . '/file.pdf'; // directory of the current theme

 	 // if a child theme is being used then use this line to get the directory
 	// $file_path = get_stylesheet_directory() . '/file.pdf';

	$attachments[] = $file_path;
	return $attachments;
}
                                    

Just edit the $file_path variable to get the file location.