PenciDesign Supporter replied
Hi,
1. If you want to add the custom content at the bottom of the single post page, install and use the Simple Post Content on this link: https://wordpress.org/plugins/simple-custom-content/.
2. You can create a custom single post template with the Elementor and apply it to the selected post at the post editor screen → Options for this Posts/Page → Custom Post Builder Template for This Post.
3. For more information about single post builder, you can read the document on this link: https://soledad.pencidesign.net/soledad-document/#posts
Regards,
PenciDesign.