How to convert to rknn?

I have custom trained a YOLO11s model with 4 classes and exported to ONNX. how to convert it to rknn?
model.export(format=‘rknn’) is not wokring properly.

rknn model compiler avoids post processing and dfl, as those are unfriendly to quantization and also better if done on cpu rather than on npu. You need to remove those while exporting onnx model, and write post processing function in your code separately.
It is descriptively mentioned here what to remove and add.
After that post processing code can be found here