jQuery : jquery slider error Uncaught TypeError: Cannot call method 'addClass' of undefined

jQuery : jquery slider error Uncaught TypeError: Cannot call method 'addClass' of undefined
To Access My Live Chat Page,
On Google, Search for "hows tech developer connect"

I promised to share a hidden feature with you, and here it is.
This is a YouTube's feature which works on Desktop.
First, Make sure this video is playing.
Then, type the letters 'awesome' on your keyboard as the next step.
You will see a flashing rainbow instead of a regular progress bar on YouTube.

A quick introduction about me,
Greetings, my name is Delphi.
I can provide you with assistance to help you answer your questions.
jQuery : jquery slider error Uncaught TypeError: Cannot call method 'addClass' of undefined
Please feel free to comment or chat with me for more detailed information.
Your input is valuable, so please comment below if you have an answer or any insights to the answer.
Your answer will be recognized and appreciated, and I will 'heart' it to show my appreciation.
call 'addClass' error slider TypeError: undefined Uncaught : method jQuery of Cannot jquery