I am using anaconda as below:
(base) C:\\Users\\xxx>conda info
active environment : base
active env location : C:\\Users\\xxx\\Documents\\ANACON
https://stackoverflow.com/a/61117831/7802476 helped me. Creating a new environment using the accepted answer didn't get my jupyter notebook to recognize the installed opencv. I could only import cv2 when I was in the environment on my terminal.
The fix was to use pip instead of conda, pip install opencv-python