The error message "ModuleNotFoundError: No module named 'bs4'" indicates that the Python module 'bs4' (Beautiful Soup) is not installed on your system.
To fix this error, you need to install the 'bs4' module. You can do this by running the following command in your terminal or command prompt:
pip install beautifulsoup4
If you are using Python 3, you may need to use pip3 instead:
pip3 install beautifulsoup4
Once the installation is complete, you should be able to import and use the 'bs4' module in your Python script without any issues.