In-feed ads are a new format that you place inside your feed to help monetize your site and provide a better user experience to your visitors. For example, a feed can be an editorial feed (e.g., a list of articles or news) or listings (e.g., a list of products, services, etc.)
I tried using the Ad Inserter plugin to add it to my Wordpress site (on homepage and category and tag ages) but it messed up the blog layout. So, I deactivated it.
Below is the settings I used :
So, you can try it and let me know if it works for your Wordpress blog.
If you've been able to successfully add the Adsense Native In-feed ads to your WordPress blog, kindly let us know.