What errors do you get when trying to install the onnx package? This is what I do to install it:
$ sudo apt-get install python3-pip libprotoc-dev protobuf-compiler
$ pip3 install onnx --verbose
What errors do you get when trying to install the onnx package? This is what I do to install it:
$ sudo apt-get install python3-pip libprotoc-dev protobuf-compiler
$ pip3 install onnx --verbose