Structured Data for SEO

Thanks to Jon_Sasala’s generosity, I added the JSON language to my Hubspot sitewide and blog headers.

But I just finished a blog post and am flummoxed on how to add the object mark-up. I can easily slip it around the the image. But I cannot figure out how to get into an HTML edit view that would allow me to place the <div> codes around thing like the header. Is this just something with the particular templates I’m using, or is there a view mode I haven’t discovered yet?

Thank you.