Display Post Comments on Non-WordPress Page

I’m trying to get the comments for post to display on a (external) non-wordpress page.

I used Intergating WordPress with your website codex to get the post to display. But I can’t find anything that explains how to incorporate the comments as well. I Tried to use the comment loop that was given in the Default wordpress theme for the single.php. But when the <?php wp_list_comments(); ?> tag is used nothing is displayed.

I always tried to recreate the code from the comment-popup.php that comes with the default wordpress theme, but when I use that, all the post have the same comments.

Right now I’m using the comment popup link to display comments.
I would like to have the comments displayed below each post, in the hidden div, that appears when “POST DATA” is clicked

Example https://youthofsuburbia.com/blog2.php