Why node and npm gives blank output but nodejs works on RaspberryPi OS?

Question

When I was trying to install ipywidgets on JupyterLab, I got the following message:

pi@raspberrypi:~ $ jupyter labextension install @jupyter-widgets/jupyterlab-manager
/usr/lib/python3/dist-packages/requests/__init__.py:91: RequestsDependencyWarning: urllib3 (1.26.2) or chardet (3.0.4) doesn't match a supported version!
  RequestsDependencyWarning)
Fail to get yarn configuration. 
An error occured.
ValueError: Please install nodejs >=10.0.0 before continuing. nodejs may be installed using conda or directly from the nodejs website.
See the log file for details:  /tmp/jupyterlab-debug-tuyrrcgt.log

But I already have those installed via apt. So I took a look in the log:

subprocess.CalledProcessError: Command '['/usr/sbin/node', 'node-version-check.js']' returned non-zero exit status 1.

Looks like node returned nothing. and I tried:

pi@raspberrypi:~ $ node -v
pi@raspberrypi:~ $ npm help
pi@raspberrypi:~ $ nodejs -v
v10.21.0

Looks like node or npm didn't setup correctly by apt. Am I doing something wrong or the Debian-buster distro is actually "busted".

The package info:

pi@raspberrypi:~ $ which node
/usr/sbin/node
pi@raspberrypi:~ $ which npm
/usr/bin/npm
pi@raspberrypi:~ $ apt-cache policy node
node:
  Installed: 0.3.2-7.4
  Candidate: 0.3.2-7.4
  Version table:
 *** 0.3.2-7.4 500
        500 http://raspbian.raspberrypi.org/raspbian buster/main armhf Packages
        100 /var/lib/dpkg/status
pi@raspberrypi:~ $ apt-cache policy npm
npm:
  Installed: 5.8.0+ds6-4+deb10u2
  Candidate: 5.8.0+ds6-4+deb10u2
  Version table:
 *** 5.8.0+ds6-4+deb10u2 500
        500 http://raspbian.raspberrypi.org/raspbian buster/main armhf Packages
        100 /var/lib/dpkg/status

I really don't want to make install node and npm, making things extra messy.

Thanks in advance !