Embed form after blog post

Hi,
I was trying to add a feedback form (such as simple-form) below each post in full view. I understood how to do this on the modular Antimatter theme but I couldn't find the right spot to put the necessary code in the blog.
Should I use both blog and modular themes (as with getgrav.org?) and set up a modular page for posts?
Thank you

Two options.

1. Add a twig include on the blog_item twig template that renders the post

2. Look at the new pageinject plugin to add it via your content