{brf_post_title:post_id} doesn't work in Admin Pages

To understand how Admin pages work, I’m recreating the Update Post admin page and using this type of admin page & URL param to get post title, content, etc to then update the value in the form.
/wp-admin/admin.php?page=brf-ap-update-post&id=29
I tried this too: {brf_post_title:{url_parameter:id}} to no avail.
Do dynamic tags not work in admin pages?

Maybe it’s user error, but I thought I’m using it correct.
Also tried just creating a new page with a heading {brf_post_title:{url_parameter:id}} and url being /?page_id=57&id=29 and I get back

OK, I turned on Dynamic Data tags… that’s a step closer.
However, the admin page is still getting the post title of the Admin Page, and not the post ID 29
when I use {brf_post_title:{url_parameter:id}}
and navigate to /wp-admin/admin.php?page=brf-ap-update-post&id=29

On the front end it works find though, to get the correct post title