Hi @lptolik
As far as I understand KNIME requires a specific version of Python, being 3.6. For that reason they use Conda to make a specific Python environment with a specific minimum set of packages with the correct versions, so all the default nodes for Python will work properly.
If you look at the KNIME Python Integration Guide you see how to achieve this.
And if you want to use something specific of Python 3.8 within KNIME I wouldn’t know whether that is already possible.