How to setup LoRa in LoPy4?

I am doing my project work on LoPy4, So I have to take data from another LoPy4 into this and display it into the computer via USB interface. So, before that we have to setup the LoRa in LoPy so that it can communicate to the another LoPy4 device. Please tell me how to do this. I also read the documentation but I couldn't find the solution.