HTML block in entry edit

I need to display a gravity calendar when editing the entry for admins only. Resolved entry editing. The shortcode display does not work. I tried the HTML block, Section description, other blocks, it doesn’t work for entries editing.
How do I display it? Any idea?

What do you mean a gravity calendar? Can you share any screenshots of what you actually mean? And to be clear, this is when editing an entry in the WordPress admin dashboard under Forms and then Edit for the entry?