Optimize content outside WP media folder?

Hi there!

I see on the old documentation site (2017) there was a way to have shortpixel optimize media from other folders.

https://shortpixel.com/blog/optimize-images-outside-media-library/

I can’t seem to find this in the UI. has this feature moved behind a paywall or something? I have some h5p plugin activity images that aren’t getting optimized.

Thanks!