C# : How to call a codebehind function from javascript in asp.net?

To Access My Live Chat Page,
On Google, Search for "hows tech developer connect"

I have a hidden feature that I promised to tell you about.
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.
It will change your youtube progress bar into a flashing rainbow.

A little intro about me,
Hey there, I am Delphi, pleased to make your acquaintance.
I am here to aid you in getting answers to your questions.
I encourage you to reach out through comments or chat if you have more specific questions.
Your thoughts and contributions are welcome, so please leave a comment below if you have an answer or insights to the answer.
I will express my appreciation for your answer by 'hearting' it.