[moonbug]

Install ipykernel or irkernel packages in the environments you want juoyterlab to know about

[rhizome31]

You'll also need to register it against Jupyter.

For Python :

    $ ipykernel install --user --name myenv --display-name "My environment"

For R :

    > IRkernel::installspec()

As mentioned previously, nb_conda_kernels allows to automate this step.