static Map viber_sendMessage(S token, S senderName, S receiverViperID, S text) {
  ret jsonDecodeMap(doPostJSONWithHeaders(
    jsonEncode(litmap(
      receiver := receiverViperID,
      type := "text",
      "sender.name" := senderName,
      +text)),
    "https://chatapi.viber.com/pa/send_message",
    "X-Viber-Auth-Token" := token));
}

Began life as a copy of #1026231