Weights can be exported in ONNX format as described in the YOLO-NAS Quickstart.
Here's an example of exporting the model, specifying input and output layer names for the YOLO-NAS-S version:
from super_gradients.training import models
net = models.get("yolo_nas_s", pretrained_weights="coco")
models.convert_to_onnx(model=net, input_shape=(3,640,640), out_path="yolo_nas_s.onnx", torch_onnx_export_kwargs={"input_names": ['input'], "output_names": ['output0', 'output1']})