Do you guys not have sms messaging, if someone I know doesn't have signal we just text them the old fashioned way
I got my brother to switch from what's app to signal finally then we got our friends who are brothers to join us, then my brothers older friends who are in the same circle joined in, then our parents recently as well. Now I'm working on getting my wife's family to let go of what's app. My wife's brother married a Brazilian ladies so he got them all on the what's app