NodeJS : Node server, Socket.io 'io is not defined'?

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 the video is currently in playing mode.
Then, type the letters 'awesome' on your keyboard as the next step.
Your YouTube progress bar will transform into a flashing rainbow.

Allow me to introduce myself briefly,
Hi, my name is Delphi, nice to meet you.
Allow me to provide support in answering your questions.
Let me know if you have more specific questions or concerns by leaving a comment or starting a chat.
Don't hesitate to provide your answer or insights by leaving a comment below.
A 'heart' from me is a way of showing appreciation for your answer.