Random Quote Machine Doesn't work in Codepen

Hello,
I originally developed my Random Quote Machine in my editor and ajax calls and twitter buttons worked fine. When I transferred my code to codepen the javascript stopped working. I’ve read a decent amount about fixing but nothing has worked so far. I’ve tried switching to HTTPS but I’m not sure that I did it properly. I’ve tried appending things to the URL. I’ve even read that you need to use jquery to make the ajax calls. The console on my browser is throwing ACCESS-CONTROL-ALLOW-ORIGIN errors but I’m still not sure if thats the only problem or if there is something else preventing my project form working on codepen. Any insight will help. Thanks.

Here is my project link:

Ok. It seemed a lot of the solutions I read about used JSONP and jQuery. Thanks for your response!

Thanks a lot! I think this will in fact be useful! I’m a little hesitant to try and dive into jQuery so soon because I’m really only a beginner in vanilla JS so I’d like to have a firmer grasp of the actual language before I start paying a lot of attention to frameworks.