Unable to use the Solver with Jupyter on macOS Sierra 10.12.6 and python 3.7

Hello everyone!

I was able to install ngsolve (older version: NGSolve-6.2.1901). But I have not problem in using the jupyter extension. When I use jupyter nbextension install --user --py ngsolve, I get the following error:

KeyError: ‘The Python module ngsolve is not a valid nbextension, it is missing the _jupyter_nbextension_paths() method.’

And when I trying to use: python3 -c ‘import ngsolve.webgui; ngsolve.webgui.howtoInstallJupyterLabextension()’

I am getting following error:
ModuleNotFoundError: No module named ‘ngsolve.webgui’

Please let me know how to fix these errors.

Thank you.