What is the correct way to add new pages to the wordpress dashboard. Not like creating a dashboard page, but instead make arbitrary pages as needed for use in lightboxes, etc.
One example, I need to query the server to get an “email preview” for a plugin I am working on. How do I create a URL that will run that particular script?
I imagine the URL would be like /wp-admin/index.php?page=my_plugin_email_preview
What functions do I need to get started?
At least: