This tutorial features the Feast Plugin, which contains theme enhancements.
The inline subscribe lets you embed a newsletter subscription form dynamically into your content, without having to edit every post.
Create the form
Create a regular WordPress page with the slug "inline-subscribe", and save it as a private post.
To do this, insert a new "Custom HTML" block and paste the code into that, then hit save.
Note that most pageviews happen on mobile devices and so you should check the the form displays well on mobile.
The form is automatically inserted after the 5th paragraph. This gives the reader some opportunity to see your photos and content and
You can modify the placement by changing the "order" field under Page Attributes.
WP Rocket Delay JS
The form is wrapped in default styling, and can be modified to match your site's design.