Troubleshooting

Confirm the module is published, assigned to a real template position, and assigned to the menu item you are testing.
With Test Mode OFF, clear the module cookie or use a private window if the popup already fired for this browser.
After changing parameters, clear Joomla cache if site caching is enabled.
If email notifications fail, check System → Global Configuration → Server → Mail Settings and send a test mail.
Legacy theme needs Fancybox assets; Modern theme does not. If CSS looks stale, hard-refresh (Ctrl+F5).
Click trigger: make sure the CSS selector matches an element that exists on the page.