[Plugin: Secondary HTML Content] Add plgin to custom post type

Check this article : https://www.jasonpaul.net/wordpress/secondary-html-plugin-works-custom-post-types/

I did see this article prior to posting. Unfortunately, this article refers to moving the secondary html block from ‘Page’ to CPT whereas I require the secondary HTML block to appear on both.

You can add secondary html block in page and CPT.

add_meta_box('secondary_content_'.$i,$title,'secondary_block_box_inner','post','normal','high',$i);
add_meta_box('secondary_content_'.$i,$title,'secondary_block_box_inner','custom-post-type','normal','high',$i);

Ahhhh nice work. It has added the box fine! Thanks, will test it out this afternoon.