How to do ONNX to TensorRT in INT8 mode?

Hello.

I am working with the subject, PyTorch to TensorRT.

With a tutorial, I could simply finish the process PyTorch to ONNX.
And, I also completed ONNX to TensorRT in fp16 mode.

However, I couldn’t take a step for ONNX to TensorRT in int8 mode.
Debugger always say that `You need to do calibration for int8*.*

Does anyone know how to do convert ONNX model to TensorRT int8 mode?

Thank you in adavance