How to Get The Excerpt of the page that displays Blog Posts

I use a static page (Blog) to display the latest posts. I want to show the excerpt of that page next to the title. However, wen I use wp_kses_post( get_the_excerpt() ), I get the excerpt of the latest post from the post archive loop. I also tried with wp_kses_post( get_the_archive_description() ) but it also does not seem to work.. Any idea how this can be done?

How do I add custom HTML to the content of an archive page’s posts?

I have a plugin with a custom post type for courses. I want to customize the content inside of the archive page’s posts and style it. I realize that the archive page is using the_content() to retrieve the posts’ content, and I’m able to use the corresponding filter to customize it; however, it’s stripping the HTML and not allowing me to style it. How do I get past this?