Conceptually what I want to do is super simple. In my plugin, I want to add a single path/route to my wordpress site:
... that loads a particular file, like:
I have played with wp-rewrite, flush_rules, add_filter('rewrite_rules_array', xxx), but all I got was for the site to accept the path but display the home page.
Clearly I'm missing something really simple, but I've googled for a while without finding what I need. Any ideas?