How to run demo and convert model

[lwxGitHub123]

Hi all,
I have downloaded the source code on ubuntu20.04 ,and enter examples/onnx/ ,
then i run command:
python3 resnet50.py --model ./models/VIM3/resnet50.nb --library ./libs/libnn_resnet50.so --picture ./data/goldfish_224x224.jpg --level 0
however ,it returns as below:

then , i enter libs ， libnn_resnet50.so is actually exist.

What's more ,when i convert the model , i can not find convert file in the onnx directory:

Could you help me please ?
Best,