ModuleNotFoundError: No module named 'typing_extensions'

I've wanted to practice coding, so I wanted to generate the video where everything is moving (not just a slideshow where I would see only the series of still pictures). My YT video says comfyUI is required for my coding purpose, so I tried installing that. I am getting ModuleNotFoundError: No module named 'typing_extensions' whenever I try launching comfyUI via python main.py. This error points to this code

from __future__ import annotations

from typing import TypedDict, Dict, Optional, Tuple
#ModuleNotFoundError: No module named 'typing_extensions'
from typing_extensions import override 
from PIL import Image
from enum import Enum
from abc import ABC
from tqdm import tqdm
from typing import TYPE_CHECKING

I have tried installing typing_extensions via pip install etc which didn't help. pipenv install did not help either. Does anyone know any clue? The link to full code is here https://pastecode.io/s/o07aet29

Please note that I didn't code this file myself, it comes with the github package I found https://github.com/comfyanonymous/ComfyUI