SageMath Kernel in jupyter-lab desktop app disconnected


I’m new in using jupyter. Yesterday, I installed the jupyterlab desktop app and I’m with some problem using SageMath Kernel.

I’m using Ubuntu 20.04.

I installed SageMath using conda with the command:

conda install -c conda-forge sage

When I start jupyter-lab from the command line Sage works. But when I use jupyterlab desktop app the kernel is disconnected after some seconds. (See image below)

I think that is related with conda but I don’t know how to fix it and I need help.

Sorry for english mistakes and thanks for the help.