WebIO is not working for Jupyter Notebook nor JupyterLab

[MartinaMJ]

Hello.
I have been facing great difficulty dealing with this problem for a few days now.
I have tried installing WebIO as it is indicated in https://juliagizmos.github.io/WebIO.jl/stable/gettingstarted/ and https://juliagizmos.github.io/WebIO.jl/stable/troubleshooting/not-detected/. When following the instructions at the second link, the Julia REPL returned that the extension should be installed through Conda or Python, which I didn't unserstand, because I already have IJulia installed. I also tried following the instructions at https://juliagizmos.github.io/WebIO.jl/latest/providers/ijulia/, but I was not able to install the webio_jupyter_extension using the command available. The windows command prompt returned that "python3" is not a command.
I also don't know if it makes any difference, but I have been launching Jupyter Notebook and Jupyter Lab through Anaconda, because it is what I commonly use. However, the kernel of the .ipynb file I have been working on is Julia 1.8.4, not a Anaconda environment.
How can this be solved?
Thank you.