I’ve figured out how to add Zotero without Firefox.
(Note: This is after I signed up and accepted the invitation to join the class.)

First I went on Zotero.org and went to the home tab where I found..

Then Click on the computer and browser you have. Since I have a Mac and want to use Google Chrome, I clicked on it. It led me to this page where I later click ‘Add to Chrome’ on the upper right corner.

When it’s been added it will notify you. Now you are free to go on any website and add to your Zotero library. It’s located in the upper right corner, next to your search bar.

This is how you add Zotero to Chrome using a Mac or any other computer! (: