How to use the custom channel large scael model?

Hi
I saw that you said that you can use the precompute model to implement a custom channel model, I was very interested in this, but I couldn't think of how to implement it, so I was eager to know how this method works, that is, how to publish the channel model path loss data you defined to Emane NEM in real time according to the node status through the precompute method.

Kind Regards
Fiona