Install
Upload it under Plugins → Add New Plugin → Upload Plugin, then activate.
Install straight from GitHub with WP-CLI:
wp plugin install https://github.com/dan0sz/widget-area-halfway-post/releases/download/v1.0.4/widget-area-halfway-post.zipNo built-in updater. New versions won't appear under Dashboard → Updates. Install new releases yourself, or let Git Updater track the repository.
Add Widget Area (Sidebar) halfway Post Content for WordPress
This plugin widgetizes the center of your posts to insert e.g. a newsletter subscription box or ads.
How does it work?
The plugin hooks into the content (the_content()) and counts the amount of headers (<h2>) and inserts a widget area right before the middle header.
Releases
2 releases. Each count is every asset in that release; expand a row for the breakdown.