How do I stop the couponsalarmalert popup

It is probably a 3rd party add on that is not able to be deleted by customizing your toolbar. If you follow these instructions, you will be able to remove it from Safari with no issues! Just visit the link below.

https://support.apple.com/en-us/HT203353

Hope this helps 🙂

Please quit the application. Force quit if necessary.

Relaunch it by holding down the shift key and clicking its icon. That action will prevent the last window state from being reloaded.

From the menu bar, select

Safari ▹ Preferences... ▹ Privacy ▹ Remove All Website Data

to get rid of any cookies or other data left by the server. Open your Downloads folder and delete anything you don't recognize.