I'd recommend downloading MeshChat:
https://github.com/liamcottle/reticulum-meshchat
It takes a bit of tinkering to get set up, but it's great fun after that. The one thing that I got stuck on was setting up the 'interfaces'. If you need some recommendations on the relays to connect to, drop me a line. I can share one or two that I'm using.
Have fun!