Solved Insert custom module into single post layout

Unfortunately, you can't do that with our child theme. You will need to edit the core plugin file template.

But there's a workaround to add custom module right above the footer:
1. You will need to use Divi Theme Builder.
2. Override the single post page footer with custom footer.
3. Replicate your current footer design in Divi Theme Builder & add your custom module right above it.

 

For that, you will need to search for a general Wordpress plugin that does the job. Just did a quick search & found this: https://www.wpbeginner.com/wp-themes/display-different-sidebar-for-each-post-and-page-for-wordpress/