I can't get see the canvas :(, got an error in console.

[anandvsr]

vendors~main.d6ae31c7fff1f92f0bb6.js:2 Exception opening new comm _handleCommOpen @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 async function (async) _handleCommOpen @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 _handleMessage @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 async function (async) _handleMessage @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 (anonymous) @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 Promise.then (async) _onWSMessage @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 vendors~main.d6ae31c7fff1f92f0bb6.js:2 Exception opening new comm _handleCommOpen @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 async function (async) _handleCommOpen @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 _handleMessage @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 async function (async) _handleMessage @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 (anonymous) @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 Promise.then (async) _onWSMessage @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 vendors~main.d6ae31c7fff1f92f0bb6.js:2 Exception opening new comm _handleCommOpen @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 async function (async) _handleCommOpen @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 _handleMessage @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 async function (async) _handleMessage @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 (anonymous) @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 Promise.then (async) _onWSMessage @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 vendors~main.d6ae31c7fff1f92f0bb6.js:2 Exception opening new comm _handleCommOpen @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 async function (async) _handleCommOpen @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 _handleMessage @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 async function (async) _handleMessage @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 (anonymous) @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 Promise.then (async) _onWSMessage @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 vendors~main.d6ae31c7fff1f92f0bb6.js:2 Exception opening new comm _handleCommOpen @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 async function (async) _handleCommOpen @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 _handleMessage @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 async function (async) _handleMessage @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 (anonymous) @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 Promise.then (async) _onWSMessage @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 vendors~main.d6ae31c7fff1f92f0bb6.js:2 Exception opening new comm _handleCommOpen @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 async function (async) _handleCommOpen @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 _handleMessage @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 async function (async) _handleMessage @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 (anonymous) @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 Promise.then (async) _onWSMessage @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 vendors~main.d6ae31c7fff1f92f0bb6.js:2 Exception opening new comm _handleCommOpen @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 async function (async) _handleCommOpen @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 _handleMessage @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 async function (async) _handleMessage @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 (anonymous) @ vendors~main.d6ae31c7fff1f92f0bb6.js:2 Promise.then (async) _onWSMessage @ vendors~main.d6ae31c7fff1f92f0bb6.js:2

Using Jupyter lab, version is 2.2.6

Sorce from: https://github.com/martinRenou/ipycanvas/blob/master/examples/hand_drawing.ipynb

[martinRenou]

What does jupyter labextension list give you?

[martinRenou]

It seems to me, looking at your screenshot, that ipywidgets also does not work in your setup.

[anandvsr]

What does jupyter labextension list give you?

[anandvsr]

jupyter labextension install @jupyter-widgets/jupyterlab-manager ipycanvas Sorry for this. I didn't install the lab extension. Now it's worked. :+1:

[martinRenou]

Nice!