Reacton is not installed in jupyterlite environment

[paddymul]

I was trying to execute the calculator demo
https://reacton.solara.dev/en/latest/_output/lab/

and from import reacton I got the following error.

---------------------------------------------------------------------------
ModuleNotFoundError                       Traceback (most recent call last)
/tmp/xpython_42/3272763547.py in <cell line: 1>()
----> 1 import reacton
      2 import reacton.ipywidgets as w
      3 
      4 
      5 @reacton.component

ModuleNotFoundError: No module named 'reacton'

Reacton does appear in this jupyterlite config file (I think)
https://github.com/widgetti/reacton/blob/master/docs/xeus-python-environment.yml