Using Button State on Electron to send SMS

General
2

I guess the SMS code you got there should work, but I know this one does work

int sendMessage(const char* telNr, const char* msg)
{
  int  ret;

  if (!strlen(telNr)) return -1;

  if (!Cellular.ready())
  {
    Cellular.on();
    Cellular.connect();
    if (!waitFor(Cellular.ready, 300000))
    {
      Log.warn("no radio connection");
      return -1;
    }
  }

  ret = Cellular.command("AT+CMGF=1\r\n");
  ret = Cellular.command("AT+CMGS=\"%s%s\",145\r\n", (telNr[0] != '+') ? "+" : "", telNr);
  ret = Cellular.command("%s\x1a", msg);
  switch (ret)
  {
    case WAIT:
      Log.info("WAITING, but probably");
    case RESP_OK:
      Log.info("Sent: '%s' to %s", msg, telNr);
      break;
    default:
      Log.warn("Message not sent (%d)", ret);
      break;
  }

  return ret;
}

But you need an SMS enabled SIM and set the APN and Particle.keepAlive() correctly

You can also try INPUT_PULLDOWN and remove your external pull-down.
And add some Serial.print() statements to show the buttonState