I have a Strix Halo 395 128GB laptop running Ubuntu from HP. I have not been able to do anything with the NPU. I was hoping it could be used for OpenCL, but does not seem so.

What examples do you have of making the NPU in this processor useful please?

All the videos I've seen of AI workloads with an AMD Strix Halo with 128GB setup have used the GPU for the processing. It has a powerful iGPU and unified memory more like Apple's M chips.