How to set up a relay radio? Old link is dead

I am trying to write elementary but correct information about how people in unfree places could set up mesh networks for sharing information securely. I have set up two nodes using the only digital devices I have (an iPad and a MacBook Pro). I hoped that I might be able to fudge my Mac somehow so that I could get it to connect with and operate the third transceiver device I just bought. However, somewhere in the hidden files in the Mac there is information that says that Meshtastic is identified with the old transistor. There is no way to get it to get a code from the screen of the third device and validate it alongside the original two devices.

I’m trying to create explanatory materials for people who are both non-Geek and also from another culture. I can’t really afford to buy another pad or computer. Is there a way to get the experience I need to be able to write an account that will really help people out?

Thanks.