display_posts_shortcode_post_class

How does this get placed into the shortcode; I am reading that you can include it, and have tried a couple of ways I thought might work, but I have not seen anywhere how it’s placed into the shortcode properly.

Example
[display-posts include_excerpt=”false”  category=”test” image_size=”medium” wrapper=”div” wrapper_class=”display-posts-listing grid” meta_key=”_thumbnail_id” display_posts_shortcode_post_class???]

Ultimate goal is this person’s need exactly, but there was no resolution: https://ww.wp.xz.cn/support/topic/add-category-or-tag-as-a-class-in-post-link/#utm_medium=referral&utm_source=facebook.com&utm_content=social

Thanks.