If you get a panicked phone call ...

[usonian]

I screensnapped this from a tweet.

In dark mode ...


The author expects agentic bots to flood messages, phone calls and email by the end of the year.

As for a redundant, encrypted means of communication (a secure channel) I personally recommend Signal messenger. It runs on everything. Includes chats, video calls, up to 8 people, and more.
https://signal.org/
Here are the features you can generally use:
https://beebom.com/best-useful-features-signal-app/
Advanced stuff
https://www.makeuseof.com/best-signal-app-features/
Signal uses an internet connection, not "messages" which sometimes come with a fat charge.

Just my suggestion.