Put that script inside a folder, share the folder with someone via Syncthing or Dropbox or whatever,

deltatouch - Decentralized, secure messenger app, powered by the chatmail core library.
<a rel="me" href="https://social.tchncs.de/@deltatouch">Fediverse</a>: @deltatouch@social.tchncs.de

Chatmail provides FOSS infrastructure for interoperable, secure, speedy and reliable end-to-end encrypted messaging. Check out clients as Arcane Chat, Bots or Delta Chat today!

[WIP] a lightweight ArcaneChat client for the command line - ArcaneChat/arcanechat-tui

How to host your own chatmail server for Delta Chat

xmppc - xmppc - Command Line Interface Tool for XMPP