Error loading server extension

I'm trying to connect to a local runtime, but I'm getting the following error: Error loading server extension —.

jupyter_http_over_ws extension initialized. Listening on /http_over_websocket
[I 00:48:59.298 NotebookApp] JupyterLab extension loaded from C:\Users\Issstezac1\anaconda3\lib\site-pack
ages\jupyterlab
[I 00:48:59.298 NotebookApp] JupyterLab application directory is C:\Users\Issstezac1\anaconda3\share\jupy
ter\lab
[W 00:48:59.314 NotebookApp] Error loading server extension —
    Traceback (most recent call last):
      File "C:\Users\Issstezac1\anaconda3\lib\site-packages\notebook\notebookapp.py", line 1670, in init_
server_extensions
        mod = importlib.import_module(modulename)
      File "C:\Users\Issstezac1\anaconda3\lib\importlib\__init__.py", line 127, in import_module
        return _bootstrap._gcd_import(name[level:], package, level)
      File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
      File "<frozen importlib._bootstrap>", line 983, in _find_and_load
      File "<frozen importlib._bootstrap>", line 965, in _find_and_load_unlocked
    ModuleNotFoundError: No module named '—'
[I 00:48:59.314 NotebookApp] Serving notebooks from local directory: C:\
[I 00:48:59.314 NotebookApp] The Jupyter Notebook is running at:
[I 00:48:59.330 NotebookApp] http://localhost:8888/?token=325c5ffe303c1c7b54b2639d3c6a256550411126dbfb974
5
[I 00:48:59.330 NotebookApp]  or http://127.0.0.1:8888/?token=325c5ffe303c1c7b54b2639d3c6a256550411126dbf
b9745
[I 00:48:59.330 NotebookApp] Use Control-C to stop this server and shut down all kernels (twice to skip c
onfirmation).
[C 00:48:59.392 NotebookApp]

    To access the notebook, open this file in a browser:
        file:///C:/Users/Issstezac1/AppData/Roaming/jupyter/runtime/nbserver-2716-open.html
    Or copy and paste one of these URLs:
        http://localhost:8888/?token=325c5ffe303c1c7b54b2639d3c6a256550411126dbfb9745
     or http://127.0.0.1:8888/?token=325c5ffe303c1c7b54b2639d3c6a256550411126dbfb9745
[W 00:50:09.451 NotebookApp] Blocking Cross Origin API request for /http_over_websocket.  Origin: https:/
/colab.research.google.com, Host: localhost:8888
[W 00:50:09.451 NotebookApp] 403 GET /http_over_websocket?min_version=0.0.7&jupyter_http_over_ws_auth_url
=http%3A%2F%2Flocalhost%3A8888%2F%3Ftoken%3D325c5ffe303c1c7b54b2639d3c6a256550411126dbfb9745 (::1) 0.00ms
 referer=None
[W 00:50:12.951 NotebookApp] Blocking Cross Origin API request for /http_over_websocket/diagnose.  Origin
: https://colab.research.google.com, Host: localhost:8888
[W 00:50:12.951 NotebookApp] 403 GET /http_over_websocket/diagnose?min_version=0.0.7 (::1) 0.00ms referer
=None

I followed every step from the documentation but I still can not connect locally. Currently, I'm using Mozilla 77.0.1 (64-bit) version. Therefore, I enabled network.websocket.allowInsecureFromHTTPS as mentioned in the specific browser settings. Even I tried the --no-browser flag as the Jupyter HTTP-over-WebSocket troubleshooting suggest. What am I doing wrong?

Any further help will be appreciated.

googlecolab / jupyter_http_over_ws

Error loading server extension — #21