@giuliovialetto I would suggest to install the necessary environment thru conda:
You can use KNIME to extract the KNIME yaml files for conda
Or you could try the environment propagation at these examples (a simple deep learning network for binary classification using the KNIME Keras integration (with a Python environment propagation) â KNIME Community Hub, Train a simple Multilayer Perceptron using TensorFlow 2 â KNIME Community Hub)