Images hidden by javascript not getting crawled, Google Images

Hey,

I have made a site using WordPress and I am using "Popup Anything" to pop up some infographics on click.

I would like these images to appear on Google Images if possible.

The crawler is not indexing them even though I requested the URL to be indexed through the search console.

Any suggestions or will I have to resort to putting them on a page directly?

Many thanks!