Our detectives are back with the following intel on this WordPress site
The site is using the Havana theme by 0codex .
We could identify 14 plugins (there might be more) - _____wordpress-seo-premium , _divi-builder , ContentViews – Post Grid & List for WordPress , divi-booster , Extended Table of Contents (with nextpage support) , kk Star Ratings , monarch_v1.3.5 , WP Sticky Sidebar , OneSignal – Web Push Notifications , pt-content-views-pro , WordPress Social Sharing Plugin – Social Warfare , Yoast SEO , WP Fastest Cache and wp-gallery-custom-links
This plugin automatically generates and inserts a table of contents (ToC) to your pages and posts, based on tags h1-h6. It can deal with nextpage-tag.