You should contact that add-ons support.

I just checked the official add-ons website for "track my package" addon and didn't see one by that name.

Is this what you installed? https://addons.mozilla.org/en-US/firefox/addon/track-package/ This is listed as the "support site" for that add-on - http://www.trackpackageextension.com/ - but I get a 403 Forbidden error when trying to view that website.

All the others that came up in a search were for overseas tracking, like in package shipping companies in southeast Asia.

the-edmeister, thanks for looking into my problem. I found the same forbidden page.