What is : 'Access-Control-Allow-Origin' header?

My Show The Local Weather pen The Map does not show up in the Codepen, it works find in the code editor . Please help ! Here is the message from Chrome console:
Access to Font at ‘https://static.codepen.io/assets/telefon/bold/af889c53-1ee3-4868-8fdc-2b310d587b50-3-b7a87e0fbd213943fae0c0ef5985635dd43fa9c24876b2725127a13ccaf4ab6a.woff’ from origin ‘https://codepen.io’ has been blocked by CORS policy: No ‘Access-Control-Allow-Origin’ header is present on the requested resource. Origin ‘https://codepen.io’ is therefore not allowed access.
js?key=AIzaSyC0riYnBemzgZq5cDZPs00l3CmiLIUp8kA&callback=initMap:96 Uncaught Kb
ih @ js?key=AIzaSyC0riYnBemzgZq5cDZPs00l3CmiLIUp8kA&callback=initMap:96
(anonymous) @ js?key=AIzaSyC0riYnBemzgZq5cDZPs00l3CmiLIUp8kA&callback=initMap:146
google.maps.Load @ js?key=AIzaSyC0riYnBemzgZq5cDZPs00l3CmiLIUp8kA&callback=initMap:21
(anonymous) @ js?key=AIzaSyC0riYnBemzgZq5cDZPs00l3CmiLIUp8kA&callback=initMap:145
(anonymous) @ js?key=AIzaSyC0riYnBemzgZq5cDZPs00l3CmiLIUp8kA&callback=initMap:146
/boomerang/iFrameKey-67809bcf-8b52-f124-4c73-4e6773dc9db4/JavaScript.js Failed to load resource: the server responded with a status of 404 ()
index.html:484 Uncaught SyntaxError: Unexpected identifier

https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Allow-Origin

I have been there . I am a newbie, do not quite understand

https://forum.freecodecamp.org/search?q=No%20'Access-Control-Allow-Origin

Thank you guys , I am going to have a look.

That is an understatement unless you define what a plugin is (Extension, Plugin, Tool). They are developed to enhance the functionality of what the user is looking for.

A lot CMS’s, ERP’s, Web Browsers & Websites all have plugins.
Sure don’t rely on them but you will use them eventually.

Here is a slower way of doing the same thing without a plugin on multiple browsers.
https://www.thegeekstuff.com/2016/09/disable-same-origin-policy/

What would you suggest Randell?