Unable to correctly install WebIO Jupyter extension in a conda environment

[tianzeliu]

I tried to install WebIO Jupyter extension in a conda environment using
python3 -m pip install webio_jupyter_extension
but the Jupyter notebook that I started in the same environment was still unable to detect it, although
pip3 show jupyterlab | grep -i location
pip3 show webio_jupyter_extension | grep -i location
give the same locations.