About Java Kernel (problem importing java JAR files)

I am using JupyterLab notebook via Anaconda on Windows10.
In the past I have installed the BeakerX software that provides a lot of Kernels for Jupyter notebooks.

I followed from the Jupyter website examples of how to import JAR files, but got errors.

So I ran these commands:

command: %classpath
output >> C:\Users\Windows\AppData\Local\Temp\beaker6539770863787598047\outDir

command: %classpath add jar jackson-core-2.14.0.jar

output>> Error
[Open Browser Console for more detailed log - Double click to close this message]
Failed to load model class ‘FoldoutModel’ from module ‘beakerx’
Error: No version of module beakerx is registered
at f.loadClass (http://localhost:8888/lab/extensions/@jupyter-widgets/jupyterlab-manager/static/134.40eaa5b8e976096d50b2.js?v=40eaa5b8e976096d50b2:1:74856)

I also ran this command and same error:
%classpath add mvn com.google.code.gson gson 2.2.4

Same Error

Hope someone can help.