How do I exclude specific images from being optimized

I’m using learndash to host online courses, and there is a known issue with SG Optimizer (and other image optimization plugins) regarding the image used for certifications. So they advise excluding the specific images from optimization (https://www.learndash.com/support/docs/troubleshooting/known-issues/#sg-optimizer-by-siteground-hosting).

Now, how do I do it with SG Optimizer?

The issue solves when I deactivate this plugin. But it comes back upon reactivation (as the image gets optimized).