how can i run visulization?

[Vonct]

After i've run data_preprare_semantickitti.py , I want to see how the pointcloud looks like.
So i run command -- python .\visualize_SemanticKITTI.py -d .\dataset\semantickitti\sequences_0.06\ -s 03
But there is an error
RuntimeError: Filename extension is not valid label file.

I noticed that it requires label file needed to has a .label filename extension.
But after data_prepare, my pointcloud&label file have the extension of .npy:
self.scan_names[self.offset] is^
.\dataset\semantickitti\sequences_0.06\03\velodyne\000000.npy^
self.label_names[self.offset] is^
.\dataset\semantickitti\sequences_0.06\03\labels\000000.npy^

So i try to visualize raw data, i run python .\visualize_SemanticKITTI.py -d .\dataset\semantickitti\sequences\ -s 03
But there is also an error:
RuntimeError: Filename extension is not valid scan file.
It requirs .npy, but raw kitii dataset has pointcloud on .bin while label on .label

So how can i run visualization?