Random Quote Machine - "Uncaught ReferenceError: $ is not defined"

Hello, I’m doing the first project of the Front-End development libraries certification and I have a problem with codepen.io, it doesn’t apply any modification I do on the page.
I’ve done the project with jQuery and I have the error ’ Uncaught ReferenceError: $ is not defined)'. Can anyone help me in order to make it work ? Thank you!
My code is :https://codepen.io/Mhm_Rs/pen/ExEvmGj

if you want to use jQuery you need to import it, otherwise it’s undefined

Thank you, now please how do I import jquery to codepen.io ?

with a jQuery CDN link. If you open the settings of the javascript panel you can search for jQuery in the add-ons section

It works now. Thank you very much!