This plugin is for adding certain text to every post, before or after.
<ul>
<li>Example : You can add a copyright notice to each post, or licensce information</li>
</ul>
For Example and Details Visit : <a href="http://www.jjtcomputing.co.uk/" title="Examples and Details" rel="nofollow ugc">http://www.jjtcomputing.co.uk/</a>
My Technical Blog is : <a href="http://www.jjtcomputing.co.uk/blog/" title="My Technical Blog" rel="nofollow ugc">http://www.jjtcomputing.co.uk/blog</a> 
If you have any queires / complaints regarding this plugin, please feel free to mail me at webmaster@jjtcomputing.co.uk. Thank you.
See my blog for updates <a href="http://www.jjtcomputing.co.uk/blog/" title="Blog" rel="nofollow ugc">http://www.jjtcomputing.co.uk/blog/</a> .
For general support, please consider posting on <a href="http://www.jjtforum.co.cc/" title="JJT Forum" rel="nofollow ugc">http://www.jjtforum.co.cc/</a>, so everyone can benefit from your answer.

Custom Post Text

This plugin is for adding certain text to every post, before or after.

SOGO

Tested with Gutenberg
Create a simple way to add javascript code to individual page post or custom post type header and footer, 
for example: add conversion code to thank you pages 
add google re-marketing code to individual pages 
and much more… 
added in version 1.3 the option to add script \ style to all pages not only individual pages, 
 this will allow you to add Google re-marketing code to the entire site or Google Analytics 
 to use it goto “settings” – “Header Footer Settings”
New Features (version 3.0): 
Added option for terms / category pages
New Features (version 2.3): 
 Added support for WooCommerce shop page.
<ol>
<li>
we support now exclude individual pages form printing the header and footer scripts, this is supported by 2 checkboxes in each page\post 
buy check it the script will not be display on this page
</li>
<li>
we added support to limit the script only for certain post type \ page
</li>
</ol>
if you like it \ use it – please rate us.
usage: 
You need to paste the code with the script tag, for example: 
 you js code

SOGO Add Script to Individual Pages Header Footer

Simple plugin to add script to header and footer for individual pages & posts

Custom Post Text vs SOGO Add Script to Individual Pages Header Footer