wpipp_exclude_from_watermark does not work

Hallo,
Using wp-image-protect plugin ( https://wordpress.org/plugins/wp-image-protect/ ) I want next :

In woocommerce products show image of products with watermark which I set in wp-image-protect plugin settings.
But I want not to show this watermark in “Order Details” page when the order is Completed.

For this I added action like:

add_action( 'woocommerce_order_status_completed', 'displo_woocommerce_order_status_completed' );
function displo_woocommerce_order_status_completed($order_id) {
    $ret= add_metadata('post', $order_id, 'wpipp_exclude_from_watermark', false);
...

I found this code in code of wp-image-protect plugin in function :
        /**
        * Save the exclude watermark field
        */
        function wpipp_add_exclude_watermark_field_save( $post, $attachment ) {
            if( isset( $attachment['wpipp_exclude_from_watermark'] ) ) {
                update_post_meta( $post['ID'], 'wpipp_exclude_from_watermark', $attachment['wpipp_exclude_from_watermark'] );
            } else {
                update_post_meta( $post['ID'], 'wpipp_exclude_from_watermark', false );
            }

            return $post;
        }

As I set this meta post value with key ‘wpipp_exclude_from_watermark’ key.
Sorry but I did not understand what is last 4th parameter “false” or “$attachment[‘wpipp_exclude_from_watermark’]” ?
How it works?

After calling my code I see row in postmeta table with post_id= Newly created order, meta_key= ‘wpipp_exclude_from_watermark’ and meta_value= ”

But the thing is that Watermark is visible anywhay on “Order Details” page when the order is Completed. I hoped as this Order (row in post table)
has row in postmeta with meta_key= ‘wpipp_exclude_from_watermark’ and meta_value= ” this image would be without watermar.

I tried to debug code of this template and did not find how this ‘wpipp_exclude_from_watermark’ works at all.
Is it break or this plugin or I did something wrong ?