Exclude a slide doesn't work

According to documentation

[portfolio_slideshow exclude=”1,2,3,4″]

You need to specify the attachment ID, which you can find in yourMedia Library by hovering over the thumbnail. You can only include attachments which are attached to the current post. Do not use these attributes simultaneously, they are mutually exclusive.

There is also an “Exclude from slideshow” checkbox in the image uploader. Instead of including or excluding slides from your slideshow, you may want to consider adding a standalone slideshow with just the images you need and inserting that instead.

Can you kindly post a link to the documentation?

https://documentation.madebyraygun.com/products/portfolio-slideshow-pro/