how to convert .pth to .onnx

[yuriycherepnev]

I don't understand Python and machine learning very well.
When I take a standard model u2net.onnx, it generates correct masks.
When I convert u2net.pth to u2net.onnx via python code, the model starts producing incorrect masks.
Why is this happening? Can someone help?

I attach screenshots of masks and code in Python.

55.jpg - original image
56.png - correct mask generated by standard model
55.png - Incorrect mask generated by converted model

command used to generate masks:
rembg i -om -m u2net_custom -x '{"model_path": "~/.u2net/u2net_converted.onnx"}' 55.jpg 55.png

python code for conversion:

[yuriycherepnev]

i find the answer