@JaeHwanChoi I cannot read the whole error message. You will not need a license to use the free h2o version. You could try and use knime’s internal Java engine as said before.
Also you might plan ahead what you want to do in which system. Now you are trying to run h2o within a python node in knime which is also possible.
Using knime, python and h2o (with Java under the hood) will require to find the right setup.
Just to make sure: knime also does support the commercial product h2o driverless AI. This uses different model formats which are not compatible with the open version and indeed will need a license and also a powerful server.
https://docs.knime.com/latest/h2o_driverless_ai_guide/#introduction